diff --git a/components/gfx/Cargo.toml b/components/gfx/Cargo.toml
index 3ef6e183239..d01aeb3ba8f 100644
--- a/components/gfx/Cargo.toml
+++ b/components/gfx/Cargo.toml
@@ -38,7 +38,7 @@ rustc-serialize = "0.3"
 serde = "0.8"
 serde_macros = "0.8"
 smallvec = "0.1"
-string_cache = {version = "0.2.23", features = ["heap_size"]}
+string_cache = {version = "0.2.25", features = ["heap_size"]}
 style = {path = "../style"}
 style_traits = {path = "../style_traits"}
 time = "0.1.12"
diff --git a/components/layout/Cargo.toml b/components/layout/Cargo.toml
index 20c8d1043f9..4dec4586604 100644
--- a/components/layout/Cargo.toml
+++ b/components/layout/Cargo.toml
@@ -36,7 +36,7 @@ script_traits = {path = "../script_traits"}
 selectors = {version = "0.11", features = ["heap_size"]}
 serde_macros = "0.8"
 smallvec = "0.1"
-string_cache = {version = "0.2.23", features = ["heap_size"]}
+string_cache = {version = "0.2.25", features = ["heap_size"]}
 style = {path = "../style"}
 style_traits = {path = "../style_traits"}
 unicode-bidi = "0.2"
diff --git a/components/layout/lib.rs b/components/layout/lib.rs
index 5991c769b2f..9f943cf48b3 100644
--- a/components/layout/lib.rs
+++ b/components/layout/lib.rs
@@ -10,7 +10,6 @@
 #![feature(plugin)]
 #![feature(raw)]
 #![feature(step_by)]
-#![feature(unsafe_no_drop_flag)]
 
 #![deny(unsafe_code)]
 
diff --git a/components/script/Cargo.toml b/components/script/Cargo.toml
index 4645d2ce419..ef7214f546b 100644
--- a/components/script/Cargo.toml
+++ b/components/script/Cargo.toml
@@ -65,7 +65,7 @@ script_traits = {path = "../script_traits"}
 selectors = {version = "0.11", features = ["heap_size"]}
 serde = "0.8"
 smallvec = "0.1"
-string_cache = {version = "0.2.23", features = ["heap_size", "unstable"]}
+string_cache = {version = "0.2.25", features = ["heap_size", "unstable"]}
 style = {path = "../style"}
 time = "0.1.12"
 url = {version = "1.2", features = ["heap_size", "query_encoding"]}
diff --git a/components/script_layout_interface/Cargo.toml b/components/script_layout_interface/Cargo.toml
index fc7519508ae..5085dc801b2 100644
--- a/components/script_layout_interface/Cargo.toml
+++ b/components/script_layout_interface/Cargo.toml
@@ -28,7 +28,7 @@ profile_traits = {path = "../profile_traits"}
 range = {path = "../range"}
 script_traits = {path = "../script_traits"}
 selectors = {version = "0.11", features = ["heap_size"]}
-string_cache = {version = "0.2.23", features = ["heap_size"]}
+string_cache = {version = "0.2.25", features = ["heap_size"]}
 style = {path = "../style"}
 url = {version = "1.2", features = ["heap_size"]}
 util = {path = "../util"}
diff --git a/components/servo/Cargo.lock b/components/servo/Cargo.lock
index 12a5a76b4c2..31725d9f1c5 100644
--- a/components/servo/Cargo.lock
+++ b/components/servo/Cargo.lock
@@ -793,7 +793,7 @@ dependencies = [
  "servo-fontconfig 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "simd 0.1.1 (git+https://github.com/huonw/simd)",
  "smallvec 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)",
- "string_cache 0.2.24 (registry+https://github.com/rust-lang/crates.io-index)",
+ "string_cache 0.2.25 (registry+https://github.com/rust-lang/crates.io-index)",
  "style 0.0.1",
  "style_traits 0.0.1",
  "time 0.1.35 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -959,8 +959,8 @@ dependencies = [
  "phf 0.7.16 (registry+https://github.com/rust-lang/crates.io-index)",
  "phf_codegen 0.7.16 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc-serialize 0.3.19 (registry+https://github.com/rust-lang/crates.io-index)",
- "string_cache 0.2.24 (registry+https://github.com/rust-lang/crates.io-index)",
- "tendril 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "string_cache 0.2.25 (registry+https://github.com/rust-lang/crates.io-index)",
+ "tendril 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "time 0.1.35 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -1086,7 +1086,7 @@ dependencies = [
 [[package]]
 name = "js"
 version = "0.1.3"
-source = "git+https://github.com/servo/rust-mozjs#9a200eab19b0035a0a1634ef527058be4738a0f6"
+source = "git+https://github.com/servo/rust-mozjs#f06428fab33a6ae633584a1a7e1bf4e3ef7914b3"
 dependencies = [
  "cmake 0.1.17 (registry+https://github.com/rust-lang/crates.io-index)",
  "heapsize 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1167,7 +1167,7 @@ dependencies = [
  "selectors 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_macros 0.8.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "smallvec 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)",
- "string_cache 0.2.24 (registry+https://github.com/rust-lang/crates.io-index)",
+ "string_cache 0.2.25 (registry+https://github.com/rust-lang/crates.io-index)",
  "style 0.0.1",
  "style_traits 0.0.1",
  "unicode-bidi 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1938,7 +1938,7 @@ dependencies = [
  "selectors 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 0.8.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "smallvec 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)",
- "string_cache 0.2.24 (registry+https://github.com/rust-lang/crates.io-index)",
+ "string_cache 0.2.25 (registry+https://github.com/rust-lang/crates.io-index)",
  "style 0.0.1",
  "time 0.1.35 (registry+https://github.com/rust-lang/crates.io-index)",
  "tinyfiledialogs 0.1.0 (git+https://github.com/jdm/tinyfiledialogs)",
@@ -1972,7 +1972,7 @@ dependencies = [
  "range 0.0.1",
  "script_traits 0.0.1",
  "selectors 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "string_cache 0.2.24 (registry+https://github.com/rust-lang/crates.io-index)",
+ "string_cache 0.2.25 (registry+https://github.com/rust-lang/crates.io-index)",
  "style 0.0.1",
  "url 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "util 0.0.1",
@@ -2031,7 +2031,7 @@ dependencies = [
  "matches 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "quickersort 2.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "smallvec 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)",
- "string_cache 0.2.24 (registry+https://github.com/rust-lang/crates.io-index)",
+ "string_cache 0.2.25 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -2208,7 +2208,7 @@ dependencies = [
 
 [[package]]
 name = "string_cache"
-version = "0.2.24"
+version = "0.2.25"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "debug_unreachable 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2248,7 +2248,7 @@ dependencies = [
  "serde 0.8.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_macros 0.8.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "smallvec 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)",
- "string_cache 0.2.24 (registry+https://github.com/rust-lang/crates.io-index)",
+ "string_cache 0.2.25 (registry+https://github.com/rust-lang/crates.io-index)",
  "style_traits 0.0.1",
  "time 0.1.35 (registry+https://github.com/rust-lang/crates.io-index)",
  "url 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2265,7 +2265,7 @@ dependencies = [
  "euclid 0.10.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc-serialize 0.3.19 (registry+https://github.com/rust-lang/crates.io-index)",
  "selectors 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "string_cache 0.2.24 (registry+https://github.com/rust-lang/crates.io-index)",
+ "string_cache 0.2.25 (registry+https://github.com/rust-lang/crates.io-index)",
  "style 0.0.1",
  "style_traits 0.0.1",
  "url 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2322,7 +2322,7 @@ dependencies = [
 
 [[package]]
 name = "tendril"
-version = "0.2.2"
+version = "0.2.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "encoding 0.2.32 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2714,8 +2714,8 @@ dependencies = [
  "phf 0.7.16 (registry+https://github.com/rust-lang/crates.io-index)",
  "phf_codegen 0.7.16 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc-serialize 0.3.19 (registry+https://github.com/rust-lang/crates.io-index)",
- "string_cache 0.2.24 (registry+https://github.com/rust-lang/crates.io-index)",
- "tendril 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "string_cache 0.2.25 (registry+https://github.com/rust-lang/crates.io-index)",
+ "tendril 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "time 0.1.35 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
diff --git a/components/style/Cargo.toml b/components/style/Cargo.toml
index daceb3178d1..3dcbbb1b9e1 100644
--- a/components/style/Cargo.toml
+++ b/components/style/Cargo.toml
@@ -44,7 +44,7 @@ selectors = "0.11"
 serde = {version = "0.8", optional = true}
 serde_macros = {version = "0.8", optional = true}
 smallvec = "0.1"
-string_cache = {version = "0.2.24", features = ["heap_size"], optional = true}
+string_cache = {version = "0.2.25", features = ["heap_size"], optional = true}
 style_traits = {path = "../style_traits"}
 time = "0.1"
 url = "1.2"
diff --git a/ports/cef/Cargo.lock b/ports/cef/Cargo.lock
index bf078c07ee1..0c8d8211543 100644
--- a/ports/cef/Cargo.lock
+++ b/ports/cef/Cargo.lock
@@ -710,7 +710,7 @@ dependencies = [
  "servo-fontconfig 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "simd 0.1.1 (git+https://github.com/huonw/simd)",
  "smallvec 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)",
- "string_cache 0.2.24 (registry+https://github.com/rust-lang/crates.io-index)",
+ "string_cache 0.2.25 (registry+https://github.com/rust-lang/crates.io-index)",
  "style 0.0.1",
  "style_traits 0.0.1",
  "time 0.1.35 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -867,8 +867,8 @@ dependencies = [
  "phf 0.7.16 (registry+https://github.com/rust-lang/crates.io-index)",
  "phf_codegen 0.7.16 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc-serialize 0.3.19 (registry+https://github.com/rust-lang/crates.io-index)",
- "string_cache 0.2.24 (registry+https://github.com/rust-lang/crates.io-index)",
- "tendril 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "string_cache 0.2.25 (registry+https://github.com/rust-lang/crates.io-index)",
+ "tendril 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "time 0.1.35 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -994,7 +994,7 @@ dependencies = [
 [[package]]
 name = "js"
 version = "0.1.3"
-source = "git+https://github.com/servo/rust-mozjs#9a200eab19b0035a0a1634ef527058be4738a0f6"
+source = "git+https://github.com/servo/rust-mozjs#f06428fab33a6ae633584a1a7e1bf4e3ef7914b3"
 dependencies = [
  "cmake 0.1.17 (registry+https://github.com/rust-lang/crates.io-index)",
  "heapsize 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1075,7 +1075,7 @@ dependencies = [
  "selectors 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_macros 0.8.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "smallvec 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)",
- "string_cache 0.2.24 (registry+https://github.com/rust-lang/crates.io-index)",
+ "string_cache 0.2.25 (registry+https://github.com/rust-lang/crates.io-index)",
  "style 0.0.1",
  "style_traits 0.0.1",
  "unicode-bidi 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1790,7 +1790,7 @@ dependencies = [
  "selectors 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 0.8.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "smallvec 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)",
- "string_cache 0.2.24 (registry+https://github.com/rust-lang/crates.io-index)",
+ "string_cache 0.2.25 (registry+https://github.com/rust-lang/crates.io-index)",
  "style 0.0.1",
  "time 0.1.35 (registry+https://github.com/rust-lang/crates.io-index)",
  "tinyfiledialogs 0.1.0 (git+https://github.com/jdm/tinyfiledialogs)",
@@ -1824,7 +1824,7 @@ dependencies = [
  "range 0.0.1",
  "script_traits 0.0.1",
  "selectors 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "string_cache 0.2.24 (registry+https://github.com/rust-lang/crates.io-index)",
+ "string_cache 0.2.25 (registry+https://github.com/rust-lang/crates.io-index)",
  "style 0.0.1",
  "url 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "util 0.0.1",
@@ -1873,7 +1873,7 @@ dependencies = [
  "matches 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "quickersort 2.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "smallvec 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)",
- "string_cache 0.2.24 (registry+https://github.com/rust-lang/crates.io-index)",
+ "string_cache 0.2.25 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -2091,7 +2091,7 @@ dependencies = [
 
 [[package]]
 name = "string_cache"
-version = "0.2.24"
+version = "0.2.25"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "debug_unreachable 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2131,7 +2131,7 @@ dependencies = [
  "serde 0.8.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_macros 0.8.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "smallvec 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)",
- "string_cache 0.2.24 (registry+https://github.com/rust-lang/crates.io-index)",
+ "string_cache 0.2.25 (registry+https://github.com/rust-lang/crates.io-index)",
  "style_traits 0.0.1",
  "time 0.1.35 (registry+https://github.com/rust-lang/crates.io-index)",
  "url 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2189,7 +2189,7 @@ dependencies = [
 
 [[package]]
 name = "tendril"
-version = "0.2.2"
+version = "0.2.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "encoding 0.2.32 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2574,8 +2574,8 @@ dependencies = [
  "phf 0.7.16 (registry+https://github.com/rust-lang/crates.io-index)",
  "phf_codegen 0.7.16 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc-serialize 0.3.19 (registry+https://github.com/rust-lang/crates.io-index)",
- "string_cache 0.2.24 (registry+https://github.com/rust-lang/crates.io-index)",
- "tendril 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "string_cache 0.2.25 (registry+https://github.com/rust-lang/crates.io-index)",
+ "tendril 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "time 0.1.35 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
diff --git a/ports/cef/interfaces/cef_app.rs b/ports/cef/interfaces/cef_app.rs
index bdd74b11ae8..b12b22304dd 100644
--- a/ports/cef/interfaces/cef_app.rs
+++ b/ports/cef/interfaces/cef_app.rs
@@ -129,8 +129,7 @@ pub struct CefApp {
 impl Clone for CefApp {
   fn clone(&self) -> CefApp{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefApp {
@@ -143,8 +142,7 @@ impl Clone for CefApp {
 impl Drop for CefApp {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -159,8 +157,7 @@ impl CefApp {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_app_t) -> CefApp {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefApp {
@@ -174,8 +171,7 @@ impl CefApp {
 
   pub fn c_object_addrefed(&self) -> *mut cef_app_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -183,10 +179,10 @@ impl CefApp {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -202,8 +198,7 @@ impl CefApp {
   //
   pub fn on_before_command_line_processing(&self, process_type: &[u16],
       command_line: interfaces::CefCommandLine) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -223,8 +218,7 @@ impl CefApp {
   //
   pub fn on_register_custom_schemes(&self,
       registrar: interfaces::CefSchemeRegistrar) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -243,8 +237,7 @@ impl CefApp {
   //
   pub fn get_resource_bundle_handler(
       &self) -> interfaces::CefResourceBundleHandler {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -260,8 +253,7 @@ impl CefApp {
   //
   pub fn get_browser_process_handler(
       &self) -> interfaces::CefBrowserProcessHandler {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -277,8 +269,7 @@ impl CefApp {
   //
   pub fn get_render_process_handler(
       &self) -> interfaces::CefRenderProcessHandler {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -305,8 +296,7 @@ impl CefWrap<*mut cef_app_t> for Option<CefApp> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_app_t) -> Option<CefApp> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefApp::from_c_object_addref(c_object))
diff --git a/ports/cef/interfaces/cef_auth_callback.rs b/ports/cef/interfaces/cef_auth_callback.rs
index f93fb47956f..1b735fc2abd 100644
--- a/ports/cef/interfaces/cef_auth_callback.rs
+++ b/ports/cef/interfaces/cef_auth_callback.rs
@@ -94,8 +94,7 @@ pub struct CefAuthCallback {
 impl Clone for CefAuthCallback {
   fn clone(&self) -> CefAuthCallback{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefAuthCallback {
@@ -108,8 +107,7 @@ impl Clone for CefAuthCallback {
 impl Drop for CefAuthCallback {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -124,8 +122,7 @@ impl CefAuthCallback {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_auth_callback_t) -> CefAuthCallback {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefAuthCallback {
@@ -139,8 +136,7 @@ impl CefAuthCallback {
 
   pub fn c_object_addrefed(&self) -> *mut cef_auth_callback_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -148,18 +144,17 @@ impl CefAuthCallback {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
   // Continue the authentication request.
   //
   pub fn cont(&self, username: &[u16], password: &[u16]) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -175,8 +170,7 @@ impl CefAuthCallback {
   // Cancel the authentication request.
   //
   pub fn cancel(&self) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -203,8 +197,7 @@ impl CefWrap<*mut cef_auth_callback_t> for Option<CefAuthCallback> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_auth_callback_t) -> Option<CefAuthCallback> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefAuthCallback::from_c_object_addref(c_object))
diff --git a/ports/cef/interfaces/cef_browser.rs b/ports/cef/interfaces/cef_browser.rs
index fb745a2de9b..8ba378bf3b5 100644
--- a/ports/cef/interfaces/cef_browser.rs
+++ b/ports/cef/interfaces/cef_browser.rs
@@ -211,8 +211,7 @@ pub struct CefBrowser {
 impl Clone for CefBrowser {
   fn clone(&self) -> CefBrowser{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefBrowser {
@@ -225,8 +224,7 @@ impl Clone for CefBrowser {
 impl Drop for CefBrowser {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -241,8 +239,7 @@ impl CefBrowser {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_browser_t) -> CefBrowser {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefBrowser {
@@ -256,8 +253,7 @@ impl CefBrowser {
 
   pub fn c_object_addrefed(&self) -> *mut cef_browser_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -265,10 +261,10 @@ impl CefBrowser {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -276,8 +272,7 @@ impl CefBrowser {
   // browser process.
   //
   pub fn get_host(&self) -> interfaces::CefBrowserHost {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -291,8 +286,7 @@ impl CefBrowser {
   // Returns true (1) if the browser can navigate backwards.
   //
   pub fn can_go_back(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -306,8 +300,7 @@ impl CefBrowser {
   // Navigate backwards.
   //
   pub fn go_back(&self) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -321,8 +314,7 @@ impl CefBrowser {
   // Returns true (1) if the browser can navigate forwards.
   //
   pub fn can_go_forward(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -336,8 +328,7 @@ impl CefBrowser {
   // Navigate forwards.
   //
   pub fn go_forward(&self) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -351,8 +342,7 @@ impl CefBrowser {
   // Returns true (1) if the browser is currently loading.
   //
   pub fn is_loading(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -366,8 +356,7 @@ impl CefBrowser {
   // Reload the current page.
   //
   pub fn reload(&self) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -381,8 +370,7 @@ impl CefBrowser {
   // Reload the current page ignoring any cached data.
   //
   pub fn reload_ignore_cache(&self) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -396,8 +384,7 @@ impl CefBrowser {
   // Stop loading the page.
   //
   pub fn stop_load(&self) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -411,8 +398,7 @@ impl CefBrowser {
   // Returns the globally unique identifier for this browser.
   //
   pub fn get_identifier(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -427,8 +413,7 @@ impl CefBrowser {
   // object.
   //
   pub fn is_same(&self, that: interfaces::CefBrowser) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -443,8 +428,7 @@ impl CefBrowser {
   // Returns true (1) if the window is a popup window.
   //
   pub fn is_popup(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -458,8 +442,7 @@ impl CefBrowser {
   // Returns true (1) if a document has been loaded in the browser.
   //
   pub fn has_document(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -473,8 +456,7 @@ impl CefBrowser {
   // Returns the main (top-level) frame for the browser window.
   //
   pub fn get_main_frame(&self) -> interfaces::CefFrame {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -488,8 +470,7 @@ impl CefBrowser {
   // Returns the focused frame for the browser window.
   //
   pub fn get_focused_frame(&self) -> interfaces::CefFrame {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -503,8 +484,7 @@ impl CefBrowser {
   // Returns the frame with the specified identifier, or NULL if not found.
   //
   pub fn get_frame_byident(&self, identifier: i64) -> interfaces::CefFrame {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -519,8 +499,7 @@ impl CefBrowser {
   // Returns the frame with the specified name, or NULL if not found.
   //
   pub fn get_frame(&self, name: &[u16]) -> interfaces::CefFrame {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -535,8 +514,7 @@ impl CefBrowser {
   // Returns the number of frames that currently exist.
   //
   pub fn get_frame_count(&self) -> libc::size_t {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -551,8 +529,7 @@ impl CefBrowser {
   //
   pub fn get_frame_identifiers(&self, identifiers_count: *mut libc::size_t,
       identifiers: *mut i64) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -568,8 +545,7 @@ impl CefBrowser {
   // Returns the names of all existing frames.
   //
   pub fn get_frame_names(&self, names: &Vec<String>) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -586,8 +562,7 @@ impl CefBrowser {
   //
   pub fn send_process_message(&self, target_process: interfaces::CefProcessId,
       message: interfaces::CefProcessMessage) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -616,8 +591,7 @@ impl CefWrap<*mut cef_browser_t> for Option<CefBrowser> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_browser_t) -> Option<CefBrowser> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefBrowser::from_c_object_addref(c_object))
@@ -674,8 +648,7 @@ pub struct CefRunFileDialogCallback {
 impl Clone for CefRunFileDialogCallback {
   fn clone(&self) -> CefRunFileDialogCallback{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefRunFileDialogCallback {
@@ -688,8 +661,7 @@ impl Clone for CefRunFileDialogCallback {
 impl Drop for CefRunFileDialogCallback {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -704,8 +676,7 @@ impl CefRunFileDialogCallback {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_run_file_dialog_callback_t) -> CefRunFileDialogCallback {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefRunFileDialogCallback {
@@ -719,8 +690,7 @@ impl CefRunFileDialogCallback {
 
   pub fn c_object_addrefed(&self) -> *mut cef_run_file_dialog_callback_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -728,10 +698,10 @@ impl CefRunFileDialogCallback {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -743,8 +713,7 @@ impl CefRunFileDialogCallback {
   //
   pub fn on_file_dialog_dismissed(&self, selected_accept_filter: libc::c_int,
       file_paths: &Vec<String>) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -773,8 +742,7 @@ impl CefWrap<*mut cef_run_file_dialog_callback_t> for Option<CefRunFileDialogCal
     }
   }
   unsafe fn to_rust(c_object: *mut cef_run_file_dialog_callback_t) -> Option<CefRunFileDialogCallback> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefRunFileDialogCallback::from_c_object_addref(c_object))
@@ -830,8 +798,7 @@ pub struct CefNavigationEntryVisitor {
 impl Clone for CefNavigationEntryVisitor {
   fn clone(&self) -> CefNavigationEntryVisitor{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefNavigationEntryVisitor {
@@ -844,8 +811,7 @@ impl Clone for CefNavigationEntryVisitor {
 impl Drop for CefNavigationEntryVisitor {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -860,8 +826,7 @@ impl CefNavigationEntryVisitor {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_navigation_entry_visitor_t) -> CefNavigationEntryVisitor {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefNavigationEntryVisitor {
@@ -875,8 +840,7 @@ impl CefNavigationEntryVisitor {
 
   pub fn c_object_addrefed(&self) -> *mut cef_navigation_entry_visitor_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -884,10 +848,10 @@ impl CefNavigationEntryVisitor {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -900,8 +864,7 @@ impl CefNavigationEntryVisitor {
   pub fn visit(&self, entry: interfaces::CefNavigationEntry,
       current: libc::c_int, index: libc::c_int,
       total: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -932,8 +895,7 @@ impl CefWrap<*mut cef_navigation_entry_visitor_t> for Option<CefNavigationEntryV
     }
   }
   unsafe fn to_rust(c_object: *mut cef_navigation_entry_visitor_t) -> Option<CefNavigationEntryVisitor> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefNavigationEntryVisitor::from_c_object_addref(c_object))
@@ -987,8 +949,7 @@ pub struct CefPdfPrintCallback {
 impl Clone for CefPdfPrintCallback {
   fn clone(&self) -> CefPdfPrintCallback{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefPdfPrintCallback {
@@ -1001,8 +962,7 @@ impl Clone for CefPdfPrintCallback {
 impl Drop for CefPdfPrintCallback {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -1017,8 +977,7 @@ impl CefPdfPrintCallback {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_pdf_print_callback_t) -> CefPdfPrintCallback {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefPdfPrintCallback {
@@ -1032,8 +991,7 @@ impl CefPdfPrintCallback {
 
   pub fn c_object_addrefed(&self) -> *mut cef_pdf_print_callback_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -1041,10 +999,10 @@ impl CefPdfPrintCallback {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -1053,8 +1011,7 @@ impl CefPdfPrintCallback {
   // successfully or false (0) otherwise.
   //
   pub fn on_pdf_print_finished(&self, path: &[u16], ok: libc::c_int) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1083,8 +1040,7 @@ impl CefWrap<*mut cef_pdf_print_callback_t> for Option<CefPdfPrintCallback> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_pdf_print_callback_t) -> Option<CefPdfPrintCallback> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefPdfPrintCallback::from_c_object_addref(c_object))
@@ -1544,8 +1500,7 @@ pub struct CefBrowserHost {
 impl Clone for CefBrowserHost {
   fn clone(&self) -> CefBrowserHost{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefBrowserHost {
@@ -1558,8 +1513,7 @@ impl Clone for CefBrowserHost {
 impl Drop for CefBrowserHost {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -1574,8 +1528,7 @@ impl CefBrowserHost {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_browser_host_t) -> CefBrowserHost {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefBrowserHost {
@@ -1589,8 +1542,7 @@ impl CefBrowserHost {
 
   pub fn c_object_addrefed(&self) -> *mut cef_browser_host_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -1598,18 +1550,17 @@ impl CefBrowserHost {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
   // Returns the hosted browser object.
   //
   pub fn get_browser(&self) -> interfaces::CefBrowser {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1630,8 +1581,7 @@ impl CefBrowserHost {
   // information.
   //
   pub fn close_browser(&self, force_close: libc::c_int) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1646,8 +1596,7 @@ impl CefBrowserHost {
   // Set whether the browser is focused.
   //
   pub fn set_focus(&self, focus: libc::c_int) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1663,8 +1612,7 @@ impl CefBrowserHost {
   // (minimized/unminimized, app hidden/unhidden, etc). Only used on Mac OS X.
   //
   pub fn set_window_visibility(&self, visible: libc::c_int) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1679,8 +1627,7 @@ impl CefBrowserHost {
   // Retrieve the window handle for this browser.
   //
   pub fn get_window_handle(&self) -> types::cef_window_handle_t {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1696,8 +1643,7 @@ impl CefBrowserHost {
   // with custom handling of modal windows.
   //
   pub fn get_opener_window_handle(&self) -> types::cef_window_handle_t {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1711,8 +1657,7 @@ impl CefBrowserHost {
   // Returns the client for this browser.
   //
   pub fn get_client(&self) -> interfaces::CefClient {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1726,8 +1671,7 @@ impl CefBrowserHost {
   // Returns the request context for this browser.
   //
   pub fn get_request_context(&self) -> interfaces::CefRequestContext {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1742,8 +1686,7 @@ impl CefBrowserHost {
   // can only be called on the UI thread.
   //
   pub fn get_zoom_level(&self) -> libc::c_double {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1759,8 +1702,7 @@ impl CefBrowserHost {
   // Otherwise, the change will be applied asynchronously on the UI thread.
   //
   pub fn set_zoom_level(&self, zoomLevel: libc::c_double) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1791,8 +1733,7 @@ impl CefBrowserHost {
       title: &[u16], default_file_path: &[u16], accept_filters: &Vec<String>,
       selected_accept_filter: libc::c_int,
       callback: interfaces::CefRunFileDialogCallback) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1812,8 +1753,7 @@ impl CefBrowserHost {
   // Download the file at |url| using cef_download_handler_t.
   //
   pub fn start_download(&self, url: &[u16]) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1828,8 +1768,7 @@ impl CefBrowserHost {
   // Print the current browser contents.
   //
   pub fn print(&self) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1848,8 +1787,7 @@ impl CefBrowserHost {
   pub fn print_to_pdf(&self, path: &[u16],
       settings: &interfaces::CefPdfPrintSettings,
       callback: interfaces::CefPdfPrintCallback) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1873,8 +1811,7 @@ impl CefBrowserHost {
   pub fn find(&self, identifier: libc::c_int, searchText: &[u16],
       forward: libc::c_int, matchCase: libc::c_int, findNext: libc::c_int) -> (
       ) {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1893,8 +1830,7 @@ impl CefBrowserHost {
   // Cancel all searches that are currently going on.
   //
   pub fn stop_finding(&self, clearSelection: libc::c_int) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1912,8 +1848,7 @@ impl CefBrowserHost {
   pub fn show_dev_tools(&self, windowInfo: &interfaces::CefWindowInfo,
       client: interfaces::CefClient, settings: &interfaces::CefBrowserSettings,
       inspect_element_at: &types::cef_point_t) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1932,8 +1867,7 @@ impl CefBrowserHost {
   // instance.
   //
   pub fn close_dev_tools(&self) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1953,8 +1887,7 @@ impl CefBrowserHost {
   pub fn get_navigation_entries(&self,
       visitor: interfaces::CefNavigationEntryVisitor,
       current_only: libc::c_int) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1970,8 +1903,7 @@ impl CefBrowserHost {
   // Set whether mouse cursor change is disabled.
   //
   pub fn set_mouse_cursor_change_disabled(&self, disabled: libc::c_int) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1986,8 +1918,7 @@ impl CefBrowserHost {
   // Returns true (1) if mouse cursor change is disabled.
   //
   pub fn is_mouse_cursor_change_disabled(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2002,8 +1933,7 @@ impl CefBrowserHost {
   // function will replace it with the specified |word|.
   //
   pub fn replace_misspelling(&self, word: &[u16]) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2018,8 +1948,7 @@ impl CefBrowserHost {
   // Add the specified |word| to the spelling dictionary.
   //
   pub fn add_word_to_dictionary(&self, word: &[u16]) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2034,8 +1963,7 @@ impl CefBrowserHost {
   // Returns true (1) if window rendering is disabled.
   //
   pub fn is_window_rendering_disabled(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2052,8 +1980,7 @@ impl CefBrowserHost {
   // function is only used when window rendering is disabled.
   //
   pub fn was_resized(&self) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2069,8 +1996,7 @@ impl CefBrowserHost {
   // hidden. This function is only used when window rendering is disabled.
   //
   pub fn was_hidden(&self, hidden: libc::c_int) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2090,8 +2016,7 @@ impl CefBrowserHost {
   // disabled.
   //
   pub fn notify_screen_info_changed(&self) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2107,8 +2032,7 @@ impl CefBrowserHost {
   // disabled.
   //
   pub fn invalidate(&self, ty: types::cef_paint_element_type_t) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2123,8 +2047,7 @@ impl CefBrowserHost {
   // Send a key event to the browser.
   //
   pub fn send_key_event(&self, event: &interfaces::CefKeyEvent) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2142,8 +2065,7 @@ impl CefBrowserHost {
   pub fn send_mouse_click_event(&self, event: &interfaces::CefMouseEvent,
       ty: types::cef_mouse_button_type_t, mouseUp: libc::c_int,
       clickCount: libc::c_int) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2163,8 +2085,7 @@ impl CefBrowserHost {
   //
   pub fn send_mouse_move_event(&self, event: &interfaces::CefMouseEvent,
       mouseLeave: libc::c_int) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2185,8 +2106,7 @@ impl CefBrowserHost {
   //
   pub fn send_mouse_wheel_event(&self, event: &interfaces::CefMouseEvent,
       deltaX: libc::c_int, deltaY: libc::c_int) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2203,8 +2123,7 @@ impl CefBrowserHost {
   // Send a focus event to the browser.
   //
   pub fn send_focus_event(&self, setFocus: libc::c_int) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2219,8 +2138,7 @@ impl CefBrowserHost {
   // Send a capture lost event to the browser.
   //
   pub fn send_capture_lost_event(&self) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2235,8 +2153,7 @@ impl CefBrowserHost {
   // resized. This function is only used on Windows and Linux.
   //
   pub fn notify_move_or_resize_started(&self) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2254,8 +2171,7 @@ impl CefBrowserHost {
   // 30). This function can only be called on the UI thread.
   //
   pub fn get_windowless_frame_rate(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2273,8 +2189,7 @@ impl CefBrowserHost {
   // set at browser creation via cef_browser_tSettings.windowless_frame_rate.
   //
   pub fn set_windowless_frame_rate(&self, frame_rate: libc::c_int) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2290,8 +2205,7 @@ impl CefBrowserHost {
   // window rendering is disabled.
   //
   pub fn get_nstext_input_context(&self) -> types::cef_text_input_context_t {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2307,8 +2221,7 @@ impl CefBrowserHost {
   //
   pub fn handle_key_event_before_text_input_client(&self,
       keyEvent: types::cef_event_handle_t) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2324,8 +2237,7 @@ impl CefBrowserHost {
   //
   pub fn handle_key_event_after_text_input_client(&self,
       keyEvent: types::cef_event_handle_t) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2348,8 +2260,7 @@ impl CefBrowserHost {
   pub fn drag_target_drag_enter(&self, drag_data: interfaces::CefDragData,
       event: &interfaces::CefMouseEvent,
       allowed_ops: types::cef_drag_operations_mask_t) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2370,8 +2281,7 @@ impl CefBrowserHost {
   //
   pub fn drag_target_drag_over(&self, event: &interfaces::CefMouseEvent,
       allowed_ops: types::cef_drag_operations_mask_t) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2389,8 +2299,7 @@ impl CefBrowserHost {
   // rendering is disabled.
   //
   pub fn drag_target_drag_leave(&self) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2408,8 +2317,7 @@ impl CefBrowserHost {
   // is disabled.
   //
   pub fn drag_target_drop(&self, event: &interfaces::CefMouseEvent) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2431,8 +2339,7 @@ impl CefBrowserHost {
   //
   pub fn drag_source_ended_at(&self, x: libc::c_int, y: libc::c_int,
       op: types::cef_drag_operations_mask_t) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2454,8 +2361,7 @@ impl CefBrowserHost {
   // This function is only used when window rendering is disabled.
   //
   pub fn drag_source_system_drag_ended(&self) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2471,8 +2377,7 @@ impl CefBrowserHost {
   // function.
   //
   pub fn composite(&self) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2488,8 +2393,7 @@ impl CefBrowserHost {
   // this function.
   //
   pub fn initialize_compositing(&self) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2558,8 +2462,7 @@ impl CefWrap<*mut cef_browser_host_t> for Option<CefBrowserHost> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_browser_host_t) -> Option<CefBrowserHost> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefBrowserHost::from_c_object_addref(c_object))
diff --git a/ports/cef/interfaces/cef_browser_process_handler.rs b/ports/cef/interfaces/cef_browser_process_handler.rs
index b4eec4be4de..eb58d839d45 100644
--- a/ports/cef/interfaces/cef_browser_process_handler.rs
+++ b/ports/cef/interfaces/cef_browser_process_handler.rs
@@ -127,8 +127,7 @@ pub struct CefBrowserProcessHandler {
 impl Clone for CefBrowserProcessHandler {
   fn clone(&self) -> CefBrowserProcessHandler{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefBrowserProcessHandler {
@@ -141,8 +140,7 @@ impl Clone for CefBrowserProcessHandler {
 impl Drop for CefBrowserProcessHandler {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -157,8 +155,7 @@ impl CefBrowserProcessHandler {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_browser_process_handler_t) -> CefBrowserProcessHandler {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefBrowserProcessHandler {
@@ -172,8 +169,7 @@ impl CefBrowserProcessHandler {
 
   pub fn c_object_addrefed(&self) -> *mut cef_browser_process_handler_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -181,10 +177,10 @@ impl CefBrowserProcessHandler {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -192,8 +188,7 @@ impl CefBrowserProcessHandler {
   // has been initialized.
   //
   pub fn on_context_initialized(&self) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -212,8 +207,7 @@ impl CefBrowserProcessHandler {
   //
   pub fn on_before_child_process_launch(&self,
       command_line: interfaces::CefCommandLine) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -233,8 +227,7 @@ impl CefBrowserProcessHandler {
   //
   pub fn on_render_process_thread_created(&self,
       extra_info: interfaces::CefListValue) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -250,8 +243,7 @@ impl CefBrowserProcessHandler {
   // provided then printing will not be supported on the Linux platform.
   //
   pub fn get_print_handler(&self) -> interfaces::CefPrintHandler {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -266,8 +258,7 @@ impl CefBrowserProcessHandler {
   // called from a thread.
   //
   pub fn on_work_available(&self) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -294,8 +285,7 @@ impl CefWrap<*mut cef_browser_process_handler_t> for Option<CefBrowserProcessHan
     }
   }
   unsafe fn to_rust(c_object: *mut cef_browser_process_handler_t) -> Option<CefBrowserProcessHandler> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefBrowserProcessHandler::from_c_object_addref(c_object))
diff --git a/ports/cef/interfaces/cef_callback.rs b/ports/cef/interfaces/cef_callback.rs
index ef2452ff71d..cec3bc49143 100644
--- a/ports/cef/interfaces/cef_callback.rs
+++ b/ports/cef/interfaces/cef_callback.rs
@@ -90,8 +90,7 @@ pub struct CefCallback {
 impl Clone for CefCallback {
   fn clone(&self) -> CefCallback{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefCallback {
@@ -104,8 +103,7 @@ impl Clone for CefCallback {
 impl Drop for CefCallback {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -120,8 +118,7 @@ impl CefCallback {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_callback_t) -> CefCallback {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefCallback {
@@ -135,8 +132,7 @@ impl CefCallback {
 
   pub fn c_object_addrefed(&self) -> *mut cef_callback_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -144,18 +140,17 @@ impl CefCallback {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
   // Continue processing.
   //
   pub fn cont(&self) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -169,8 +164,7 @@ impl CefCallback {
   // Cancel processing.
   //
   pub fn cancel(&self) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -197,8 +191,7 @@ impl CefWrap<*mut cef_callback_t> for Option<CefCallback> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_callback_t) -> Option<CefCallback> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefCallback::from_c_object_addref(c_object))
@@ -247,8 +240,7 @@ pub struct CefCompletionCallback {
 impl Clone for CefCompletionCallback {
   fn clone(&self) -> CefCompletionCallback{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefCompletionCallback {
@@ -261,8 +253,7 @@ impl Clone for CefCompletionCallback {
 impl Drop for CefCompletionCallback {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -277,8 +268,7 @@ impl CefCompletionCallback {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_completion_callback_t) -> CefCompletionCallback {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefCompletionCallback {
@@ -292,8 +282,7 @@ impl CefCompletionCallback {
 
   pub fn c_object_addrefed(&self) -> *mut cef_completion_callback_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -301,18 +290,17 @@ impl CefCompletionCallback {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
   // Method that will be called once the task is complete.
   //
   pub fn on_complete(&self) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -339,8 +327,7 @@ impl CefWrap<*mut cef_completion_callback_t> for Option<CefCompletionCallback> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_completion_callback_t) -> Option<CefCompletionCallback> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefCompletionCallback::from_c_object_addref(c_object))
diff --git a/ports/cef/interfaces/cef_client.rs b/ports/cef/interfaces/cef_client.rs
index e49632d5f96..5c03330bde4 100644
--- a/ports/cef/interfaces/cef_client.rs
+++ b/ports/cef/interfaces/cef_client.rs
@@ -179,8 +179,7 @@ pub struct CefClient {
 impl Clone for CefClient {
   fn clone(&self) -> CefClient{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefClient {
@@ -193,8 +192,7 @@ impl Clone for CefClient {
 impl Drop for CefClient {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -209,8 +207,7 @@ impl CefClient {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_client_t) -> CefClient {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefClient {
@@ -224,8 +221,7 @@ impl CefClient {
 
   pub fn c_object_addrefed(&self) -> *mut cef_client_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -233,10 +229,10 @@ impl CefClient {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -244,8 +240,7 @@ impl CefClient {
   // implementation will be used.
   //
   pub fn get_context_menu_handler(&self) -> interfaces::CefContextMenuHandler {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -260,8 +255,7 @@ impl CefClient {
   // implementation will be used.
   //
   pub fn get_dialog_handler(&self) -> interfaces::CefDialogHandler {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -275,8 +269,7 @@ impl CefClient {
   // Return the handler for browser display state events.
   //
   pub fn get_display_handler(&self) -> interfaces::CefDisplayHandler {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -291,8 +284,7 @@ impl CefClient {
   // will not be allowed.
   //
   pub fn get_download_handler(&self) -> interfaces::CefDownloadHandler {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -306,8 +298,7 @@ impl CefClient {
   // Return the handler for drag events.
   //
   pub fn get_drag_handler(&self) -> interfaces::CefDragHandler {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -321,8 +312,7 @@ impl CefClient {
   // Return the handler for find result events.
   //
   pub fn get_find_handler(&self) -> interfaces::CefFindHandler {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -336,8 +326,7 @@ impl CefClient {
   // Return the handler for focus events.
   //
   pub fn get_focus_handler(&self) -> interfaces::CefFocusHandler {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -352,8 +341,7 @@ impl CefClient {
   // provided geolocation access will be denied by default.
   //
   pub fn get_geolocation_handler(&self) -> interfaces::CefGeolocationHandler {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -368,8 +356,7 @@ impl CefClient {
   // default implementation will be used.
   //
   pub fn get_jsdialog_handler(&self) -> interfaces::CefJSDialogHandler {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -383,8 +370,7 @@ impl CefClient {
   // Return the handler for keyboard events.
   //
   pub fn get_keyboard_handler(&self) -> interfaces::CefKeyboardHandler {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -398,8 +384,7 @@ impl CefClient {
   // Return the handler for browser life span events.
   //
   pub fn get_life_span_handler(&self) -> interfaces::CefLifeSpanHandler {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -413,8 +398,7 @@ impl CefClient {
   // Return the handler for browser load status events.
   //
   pub fn get_load_handler(&self) -> interfaces::CefLoadHandler {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -428,8 +412,7 @@ impl CefClient {
   // Return the handler for off-screen rendering events.
   //
   pub fn get_render_handler(&self) -> interfaces::CefRenderHandler {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -443,8 +426,7 @@ impl CefClient {
   // Return the handler for browser request events.
   //
   pub fn get_request_handler(&self) -> interfaces::CefRequestHandler {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -462,8 +444,7 @@ impl CefClient {
   pub fn on_process_message_received(&self, browser: interfaces::CefBrowser,
       source_process: interfaces::CefProcessId,
       message: interfaces::CefProcessMessage) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -493,8 +474,7 @@ impl CefWrap<*mut cef_client_t> for Option<CefClient> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_client_t) -> Option<CefClient> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefClient::from_c_object_addref(c_object))
diff --git a/ports/cef/interfaces/cef_command_line.rs b/ports/cef/interfaces/cef_command_line.rs
index d8926bf76c1..489af9f5ceb 100644
--- a/ports/cef/interfaces/cef_command_line.rs
+++ b/ports/cef/interfaces/cef_command_line.rs
@@ -229,8 +229,7 @@ pub struct CefCommandLine {
 impl Clone for CefCommandLine {
   fn clone(&self) -> CefCommandLine{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefCommandLine {
@@ -243,8 +242,7 @@ impl Clone for CefCommandLine {
 impl Drop for CefCommandLine {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -259,8 +257,7 @@ impl CefCommandLine {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_command_line_t) -> CefCommandLine {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefCommandLine {
@@ -274,8 +271,7 @@ impl CefCommandLine {
 
   pub fn c_object_addrefed(&self) -> *mut cef_command_line_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -283,10 +279,10 @@ impl CefCommandLine {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -294,8 +290,7 @@ impl CefCommandLine {
   // if this function returns false (0).
   //
   pub fn is_valid(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -310,8 +305,7 @@ impl CefCommandLine {
   // expose read-only objects.
   //
   pub fn is_read_only(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -325,8 +319,7 @@ impl CefCommandLine {
   // Returns a writable copy of this object.
   //
   pub fn copy(&self) -> interfaces::CefCommandLine {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -342,8 +335,7 @@ impl CefCommandLine {
   // supported on non-Windows platforms.
   //
   pub fn init_from_argv(&self, argc: libc::c_int, argv: &&str) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -360,8 +352,7 @@ impl CefCommandLine {
   // GetCommandLineW(). This function is only supported on Windows.
   //
   pub fn init_from_string(&self, command_line: &[u16]) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -377,8 +368,7 @@ impl CefCommandLine {
   // component unchanged.
   //
   pub fn reset(&self) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -393,8 +383,7 @@ impl CefCommandLine {
   // array: { program, [(--|-|/)switch[=value]]*, [--], [argument]* }
   //
   pub fn get_argv(&self, argv: &Vec<String>) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -411,8 +400,7 @@ impl CefCommandLine {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_command_line_string(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -427,8 +415,7 @@ impl CefCommandLine {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_program(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -442,8 +429,7 @@ impl CefCommandLine {
   // Set the program part of the command line string (the first item).
   //
   pub fn set_program(&self, program: &[u16]) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -458,8 +444,7 @@ impl CefCommandLine {
   // Returns true (1) if the command line has switches.
   //
   pub fn has_switches(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -473,8 +458,7 @@ impl CefCommandLine {
   // Returns true (1) if the command line contains the given switch.
   //
   pub fn has_switch(&self, name: &[u16]) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -491,8 +475,7 @@ impl CefCommandLine {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_switch_value(&self, name: &[u16]) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -508,8 +491,7 @@ impl CefCommandLine {
   // NULL string is returned.
   //
   pub fn get_switches(&self, switches: HashMap<String,String>) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -525,8 +507,7 @@ impl CefCommandLine {
   // pass an NULL value string.
   //
   pub fn append_switch(&self, name: &[u16]) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -541,8 +522,7 @@ impl CefCommandLine {
   // Add a switch with the specified value to the end of the command line.
   //
   pub fn append_switch_with_value(&self, name: &[u16], value: &[u16]) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -558,8 +538,7 @@ impl CefCommandLine {
   // True if there are remaining command line arguments.
   //
   pub fn has_arguments(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -573,8 +552,7 @@ impl CefCommandLine {
   // Get the remaining command line arguments.
   //
   pub fn get_arguments(&self, arguments: &Vec<String>) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -589,8 +567,7 @@ impl CefCommandLine {
   // Add an argument to the end of the command line.
   //
   pub fn append_argument(&self, argument: &[u16]) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -606,8 +583,7 @@ impl CefCommandLine {
   // "valgrind" or "gdb --args".
   //
   pub fn prepend_wrapper(&self, wrapper: &[u16]) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -658,8 +634,7 @@ impl CefWrap<*mut cef_command_line_t> for Option<CefCommandLine> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_command_line_t) -> Option<CefCommandLine> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefCommandLine::from_c_object_addref(c_object))
diff --git a/ports/cef/interfaces/cef_context_menu_handler.rs b/ports/cef/interfaces/cef_context_menu_handler.rs
index 27373d33eab..ed61ad30bd3 100644
--- a/ports/cef/interfaces/cef_context_menu_handler.rs
+++ b/ports/cef/interfaces/cef_context_menu_handler.rs
@@ -122,8 +122,7 @@ pub struct CefContextMenuHandler {
 impl Clone for CefContextMenuHandler {
   fn clone(&self) -> CefContextMenuHandler{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefContextMenuHandler {
@@ -136,8 +135,7 @@ impl Clone for CefContextMenuHandler {
 impl Drop for CefContextMenuHandler {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -152,8 +150,7 @@ impl CefContextMenuHandler {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_context_menu_handler_t) -> CefContextMenuHandler {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefContextMenuHandler {
@@ -167,8 +164,7 @@ impl CefContextMenuHandler {
 
   pub fn c_object_addrefed(&self) -> *mut cef_context_menu_handler_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -176,10 +172,10 @@ impl CefContextMenuHandler {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -192,8 +188,7 @@ impl CefContextMenuHandler {
   pub fn on_before_context_menu(&self, browser: interfaces::CefBrowser,
       frame: interfaces::CefFrame, params: interfaces::CefContextMenuParams,
       model: interfaces::CefMenuModel) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -220,8 +215,7 @@ impl CefContextMenuHandler {
       frame: interfaces::CefFrame, params: interfaces::CefContextMenuParams,
       command_id: libc::c_int,
       event_flags: types::cef_event_flags_t) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -242,8 +236,7 @@ impl CefContextMenuHandler {
   //
   pub fn on_context_menu_dismissed(&self, browser: interfaces::CefBrowser,
       frame: interfaces::CefFrame) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -272,8 +265,7 @@ impl CefWrap<*mut cef_context_menu_handler_t> for Option<CefContextMenuHandler>
     }
   }
   unsafe fn to_rust(c_object: *mut cef_context_menu_handler_t) -> Option<CefContextMenuHandler> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefContextMenuHandler::from_c_object_addref(c_object))
@@ -450,8 +442,7 @@ pub struct CefContextMenuParams {
 impl Clone for CefContextMenuParams {
   fn clone(&self) -> CefContextMenuParams{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefContextMenuParams {
@@ -464,8 +455,7 @@ impl Clone for CefContextMenuParams {
 impl Drop for CefContextMenuParams {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -480,8 +470,7 @@ impl CefContextMenuParams {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_context_menu_params_t) -> CefContextMenuParams {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefContextMenuParams {
@@ -495,8 +484,7 @@ impl CefContextMenuParams {
 
   pub fn c_object_addrefed(&self) -> *mut cef_context_menu_params_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -504,10 +492,10 @@ impl CefContextMenuParams {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -515,8 +503,7 @@ impl CefContextMenuParams {
   // Coords are relative to the associated RenderView's origin.
   //
   pub fn get_xcoord(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -531,8 +518,7 @@ impl CefContextMenuParams {
   // Coords are relative to the associated RenderView's origin.
   //
   pub fn get_ycoord(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -547,8 +533,7 @@ impl CefContextMenuParams {
   // invoked on.
   //
   pub fn get_type_flags(&self) -> types::cef_context_menu_type_flags_t {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -564,8 +549,7 @@ impl CefContextMenuParams {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_link_url(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -581,8 +565,7 @@ impl CefContextMenuParams {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_unfiltered_link_url(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -598,8 +581,7 @@ impl CefContextMenuParams {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_source_url(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -614,8 +596,7 @@ impl CefContextMenuParams {
   // NULL contents.
   //
   pub fn has_image_contents(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -630,8 +611,7 @@ impl CefContextMenuParams {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_page_url(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -646,8 +626,7 @@ impl CefContextMenuParams {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_frame_url(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -663,8 +642,7 @@ impl CefContextMenuParams {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_frame_charset(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -678,8 +656,7 @@ impl CefContextMenuParams {
   // Returns the type of context node that the context menu was invoked on.
   //
   pub fn get_media_type(&self) -> types::cef_context_menu_media_type_t {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -695,8 +672,7 @@ impl CefContextMenuParams {
   //
   pub fn get_media_state_flags(
       &self) -> types::cef_context_menu_media_state_flags_t {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -712,8 +688,7 @@ impl CefContextMenuParams {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_selection_text(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -729,8 +704,7 @@ impl CefContextMenuParams {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_misspelled_word(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -747,8 +721,7 @@ impl CefContextMenuParams {
   //
   pub fn get_dictionary_suggestions(&self,
       suggestions: &Vec<String>) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -763,8 +736,7 @@ impl CefContextMenuParams {
   // Returns true (1) if the context menu was invoked on an editable node.
   //
   pub fn is_editable(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -779,8 +751,7 @@ impl CefContextMenuParams {
   // spell-check is enabled.
   //
   pub fn is_spell_check_enabled(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -796,8 +767,7 @@ impl CefContextMenuParams {
   //
   pub fn get_edit_state_flags(
       &self) -> types::cef_context_menu_edit_state_flags_t {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -824,8 +794,7 @@ impl CefWrap<*mut cef_context_menu_params_t> for Option<CefContextMenuParams> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_context_menu_params_t) -> Option<CefContextMenuParams> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefContextMenuParams::from_c_object_addref(c_object))
diff --git a/ports/cef/interfaces/cef_cookie.rs b/ports/cef/interfaces/cef_cookie.rs
index d938f8b79ef..257ebeea4c9 100644
--- a/ports/cef/interfaces/cef_cookie.rs
+++ b/ports/cef/interfaces/cef_cookie.rs
@@ -161,8 +161,7 @@ pub struct CefCookieManager {
 impl Clone for CefCookieManager {
   fn clone(&self) -> CefCookieManager{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefCookieManager {
@@ -175,8 +174,7 @@ impl Clone for CefCookieManager {
 impl Drop for CefCookieManager {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -191,8 +189,7 @@ impl CefCookieManager {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_cookie_manager_t) -> CefCookieManager {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefCookieManager {
@@ -206,8 +203,7 @@ impl CefCookieManager {
 
   pub fn c_object_addrefed(&self) -> *mut cef_cookie_manager_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -215,10 +211,10 @@ impl CefCookieManager {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -229,8 +225,7 @@ impl CefCookieManager {
   //
   pub fn set_supported_schemes(&self, schemes: &Vec<String>,
       callback: interfaces::CefCompletionCallback) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -249,8 +244,7 @@ impl CefCookieManager {
   //
   pub fn visit_all_cookies(&self,
       visitor: interfaces::CefCookieVisitor) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -270,8 +264,7 @@ impl CefCookieManager {
   //
   pub fn visit_url_cookies(&self, url: &[u16], includeHttpOnly: libc::c_int,
       visitor: interfaces::CefCookieVisitor) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -295,8 +288,7 @@ impl CefCookieManager {
   //
   pub fn set_cookie(&self, url: &[u16], cookie: &interfaces::CefCookie,
       callback: interfaces::CefSetCookieCallback) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -322,8 +314,7 @@ impl CefCookieManager {
   //
   pub fn delete_cookies(&self, url: &[u16], cookie_name: &[u16],
       callback: interfaces::CefDeleteCookiesCallback) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -349,8 +340,7 @@ impl CefCookieManager {
   pub fn set_storage_path(&self, path: &[u16],
       persist_session_cookies: libc::c_int,
       callback: interfaces::CefCompletionCallback) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -370,8 +360,7 @@ impl CefCookieManager {
   //
   pub fn flush_store(&self,
       callback: interfaces::CefCompletionCallback) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -436,8 +425,7 @@ impl CefWrap<*mut cef_cookie_manager_t> for Option<CefCookieManager> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_cookie_manager_t) -> Option<CefCookieManager> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefCookieManager::from_c_object_addref(c_object))
@@ -493,8 +481,7 @@ pub struct CefCookieVisitor {
 impl Clone for CefCookieVisitor {
   fn clone(&self) -> CefCookieVisitor{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefCookieVisitor {
@@ -507,8 +494,7 @@ impl Clone for CefCookieVisitor {
 impl Drop for CefCookieVisitor {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -523,8 +509,7 @@ impl CefCookieVisitor {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_cookie_visitor_t) -> CefCookieVisitor {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefCookieVisitor {
@@ -538,8 +523,7 @@ impl CefCookieVisitor {
 
   pub fn c_object_addrefed(&self) -> *mut cef_cookie_visitor_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -547,10 +531,10 @@ impl CefCookieVisitor {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -562,8 +546,7 @@ impl CefCookieVisitor {
   //
   pub fn visit(&self, cookie: &interfaces::CefCookie, count: libc::c_int,
       total: libc::c_int, deleteCookie: &mut libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -594,8 +577,7 @@ impl CefWrap<*mut cef_cookie_visitor_t> for Option<CefCookieVisitor> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_cookie_visitor_t) -> Option<CefCookieVisitor> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefCookieVisitor::from_c_object_addref(c_object))
@@ -647,8 +629,7 @@ pub struct CefSetCookieCallback {
 impl Clone for CefSetCookieCallback {
   fn clone(&self) -> CefSetCookieCallback{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefSetCookieCallback {
@@ -661,8 +642,7 @@ impl Clone for CefSetCookieCallback {
 impl Drop for CefSetCookieCallback {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -677,8 +657,7 @@ impl CefSetCookieCallback {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_set_cookie_callback_t) -> CefSetCookieCallback {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefSetCookieCallback {
@@ -692,8 +671,7 @@ impl CefSetCookieCallback {
 
   pub fn c_object_addrefed(&self) -> *mut cef_set_cookie_callback_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -701,10 +679,10 @@ impl CefSetCookieCallback {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -712,8 +690,7 @@ impl CefSetCookieCallback {
   // the cookie was set successfully.
   //
   pub fn on_complete(&self, success: libc::c_int) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -741,8 +718,7 @@ impl CefWrap<*mut cef_set_cookie_callback_t> for Option<CefSetCookieCallback> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_set_cookie_callback_t) -> Option<CefSetCookieCallback> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefSetCookieCallback::from_c_object_addref(c_object))
@@ -795,8 +771,7 @@ pub struct CefDeleteCookiesCallback {
 impl Clone for CefDeleteCookiesCallback {
   fn clone(&self) -> CefDeleteCookiesCallback{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefDeleteCookiesCallback {
@@ -809,8 +784,7 @@ impl Clone for CefDeleteCookiesCallback {
 impl Drop for CefDeleteCookiesCallback {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -825,8 +799,7 @@ impl CefDeleteCookiesCallback {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_delete_cookies_callback_t) -> CefDeleteCookiesCallback {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefDeleteCookiesCallback {
@@ -840,8 +813,7 @@ impl CefDeleteCookiesCallback {
 
   pub fn c_object_addrefed(&self) -> *mut cef_delete_cookies_callback_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -849,10 +821,10 @@ impl CefDeleteCookiesCallback {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -860,8 +832,7 @@ impl CefDeleteCookiesCallback {
   // number of cookies that were deleted or -1 if unknown.
   //
   pub fn on_complete(&self, num_deleted: libc::c_int) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -889,8 +860,7 @@ impl CefWrap<*mut cef_delete_cookies_callback_t> for Option<CefDeleteCookiesCall
     }
   }
   unsafe fn to_rust(c_object: *mut cef_delete_cookies_callback_t) -> Option<CefDeleteCookiesCallback> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefDeleteCookiesCallback::from_c_object_addref(c_object))
diff --git a/ports/cef/interfaces/cef_dialog_handler.rs b/ports/cef/interfaces/cef_dialog_handler.rs
index d31ffc442c6..e0b98a14bc1 100644
--- a/ports/cef/interfaces/cef_dialog_handler.rs
+++ b/ports/cef/interfaces/cef_dialog_handler.rs
@@ -97,8 +97,7 @@ pub struct CefFileDialogCallback {
 impl Clone for CefFileDialogCallback {
   fn clone(&self) -> CefFileDialogCallback{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefFileDialogCallback {
@@ -111,8 +110,7 @@ impl Clone for CefFileDialogCallback {
 impl Drop for CefFileDialogCallback {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -127,8 +125,7 @@ impl CefFileDialogCallback {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_file_dialog_callback_t) -> CefFileDialogCallback {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefFileDialogCallback {
@@ -142,8 +139,7 @@ impl CefFileDialogCallback {
 
   pub fn c_object_addrefed(&self) -> *mut cef_file_dialog_callback_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -151,10 +147,10 @@ impl CefFileDialogCallback {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -166,8 +162,7 @@ impl CefFileDialogCallback {
   //
   pub fn cont(&self, selected_accept_filter: libc::c_int,
       file_paths: &Vec<String>) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -183,8 +178,7 @@ impl CefFileDialogCallback {
   // Cancel the file selection.
   //
   pub fn cancel(&self) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -211,8 +205,7 @@ impl CefWrap<*mut cef_file_dialog_callback_t> for Option<CefFileDialogCallback>
     }
   }
   unsafe fn to_rust(c_object: *mut cef_file_dialog_callback_t) -> Option<CefFileDialogCallback> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefFileDialogCallback::from_c_object_addref(c_object))
@@ -280,8 +273,7 @@ pub struct CefDialogHandler {
 impl Clone for CefDialogHandler {
   fn clone(&self) -> CefDialogHandler{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefDialogHandler {
@@ -294,8 +286,7 @@ impl Clone for CefDialogHandler {
 impl Drop for CefDialogHandler {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -310,8 +301,7 @@ impl CefDialogHandler {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_dialog_handler_t) -> CefDialogHandler {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefDialogHandler {
@@ -325,8 +315,7 @@ impl CefDialogHandler {
 
   pub fn c_object_addrefed(&self) -> *mut cef_dialog_handler_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -334,10 +323,10 @@ impl CefDialogHandler {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -360,8 +349,7 @@ impl CefDialogHandler {
       default_file_path: &[u16], accept_filters: &Vec<String>,
       selected_accept_filter: libc::c_int,
       callback: interfaces::CefFileDialogCallback) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -395,8 +383,7 @@ impl CefWrap<*mut cef_dialog_handler_t> for Option<CefDialogHandler> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_dialog_handler_t) -> Option<CefDialogHandler> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefDialogHandler::from_c_object_addref(c_object))
diff --git a/ports/cef/interfaces/cef_display_handler.rs b/ports/cef/interfaces/cef_display_handler.rs
index b1652738a42..c2cdbae987e 100644
--- a/ports/cef/interfaces/cef_display_handler.rs
+++ b/ports/cef/interfaces/cef_display_handler.rs
@@ -144,8 +144,7 @@ pub struct CefDisplayHandler {
 impl Clone for CefDisplayHandler {
   fn clone(&self) -> CefDisplayHandler{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefDisplayHandler {
@@ -158,8 +157,7 @@ impl Clone for CefDisplayHandler {
 impl Drop for CefDisplayHandler {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -174,8 +172,7 @@ impl CefDisplayHandler {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_display_handler_t) -> CefDisplayHandler {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefDisplayHandler {
@@ -189,8 +186,7 @@ impl CefDisplayHandler {
 
   pub fn c_object_addrefed(&self) -> *mut cef_display_handler_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -198,10 +194,10 @@ impl CefDisplayHandler {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -209,8 +205,7 @@ impl CefDisplayHandler {
   //
   pub fn on_address_change(&self, browser: interfaces::CefBrowser,
       frame: interfaces::CefFrame, url: &[u16]) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -228,8 +223,7 @@ impl CefDisplayHandler {
   //
   pub fn on_title_change(&self, browser: interfaces::CefBrowser,
       title: &[u16]) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -246,8 +240,7 @@ impl CefDisplayHandler {
   //
   pub fn on_favicon_urlchange(&self, browser: interfaces::CefBrowser,
       icon_urls: &Vec<String>) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -268,8 +261,7 @@ impl CefDisplayHandler {
   //
   pub fn on_fullscreen_mode_change(&self, browser: interfaces::CefBrowser,
       fullscreen: libc::c_int) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -291,8 +283,7 @@ impl CefDisplayHandler {
   //
   pub fn on_tooltip(&self, browser: interfaces::CefBrowser,
       text: *mut types::cef_string_t) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -310,8 +301,7 @@ impl CefDisplayHandler {
   //
   pub fn on_status_message(&self, browser: interfaces::CefBrowser,
       value: &[u16]) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -329,8 +319,7 @@ impl CefDisplayHandler {
   //
   pub fn on_console_message(&self, browser: interfaces::CefBrowser,
       message: &[u16], source: &[u16], line: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -361,8 +350,7 @@ impl CefWrap<*mut cef_display_handler_t> for Option<CefDisplayHandler> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_display_handler_t) -> Option<CefDisplayHandler> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefDisplayHandler::from_c_object_addref(c_object))
diff --git a/ports/cef/interfaces/cef_dom.rs b/ports/cef/interfaces/cef_dom.rs
index 6fc2f880675..09ca9a4ec12 100644
--- a/ports/cef/interfaces/cef_dom.rs
+++ b/ports/cef/interfaces/cef_dom.rs
@@ -92,8 +92,7 @@ pub struct CefDOMVisitor {
 impl Clone for CefDOMVisitor {
   fn clone(&self) -> CefDOMVisitor{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefDOMVisitor {
@@ -106,8 +105,7 @@ impl Clone for CefDOMVisitor {
 impl Drop for CefDOMVisitor {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -122,8 +120,7 @@ impl CefDOMVisitor {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_domvisitor_t) -> CefDOMVisitor {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefDOMVisitor {
@@ -137,8 +134,7 @@ impl CefDOMVisitor {
 
   pub fn c_object_addrefed(&self) -> *mut cef_domvisitor_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -146,10 +142,10 @@ impl CefDOMVisitor {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -160,8 +156,7 @@ impl CefDOMVisitor {
   // of this function.
   //
   pub fn visit(&self, document: interfaces::CefDOMDocument) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null(){
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -189,8 +184,7 @@ impl CefWrap<*mut cef_domvisitor_t> for Option<CefDOMVisitor> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_domvisitor_t) -> Option<CefDOMVisitor> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefDOMVisitor::from_c_object_addref(c_object))
@@ -325,8 +319,7 @@ pub struct CefDOMDocument {
 impl Clone for CefDOMDocument {
   fn clone(&self) -> CefDOMDocument{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefDOMDocument {
@@ -339,8 +332,7 @@ impl Clone for CefDOMDocument {
 impl Drop for CefDOMDocument {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -355,8 +347,7 @@ impl CefDOMDocument {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_domdocument_t) -> CefDOMDocument {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefDOMDocument {
@@ -370,8 +361,7 @@ impl CefDOMDocument {
 
   pub fn c_object_addrefed(&self) -> *mut cef_domdocument_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -379,18 +369,17 @@ impl CefDOMDocument {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
   // Returns the document type.
   //
   pub fn get_type(&self) -> types::cef_dom_document_type_t {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null(){
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -404,8 +393,7 @@ impl CefDOMDocument {
   // Returns the root document node.
   //
   pub fn get_document(&self) -> interfaces::CefDOMNode {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null(){
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -419,8 +407,7 @@ impl CefDOMDocument {
   // Returns the BODY node of an HTML document.
   //
   pub fn get_body(&self) -> interfaces::CefDOMNode {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null(){
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -434,8 +421,7 @@ impl CefDOMDocument {
   // Returns the HEAD node of an HTML document.
   //
   pub fn get_head(&self) -> interfaces::CefDOMNode {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null(){
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -450,8 +436,7 @@ impl CefDOMDocument {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_title(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null(){
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -465,8 +450,7 @@ impl CefDOMDocument {
   // Returns the document element with the specified ID value.
   //
   pub fn get_element_by_id(&self, id: &[u16]) -> interfaces::CefDOMNode {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null(){
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -481,8 +465,7 @@ impl CefDOMDocument {
   // Returns the node that currently has keyboard focus.
   //
   pub fn get_focused_node(&self) -> interfaces::CefDOMNode {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null(){
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -496,8 +479,7 @@ impl CefDOMDocument {
   // Returns true (1) if a portion of the document is selected.
   //
   pub fn has_selection(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null(){
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -511,8 +493,7 @@ impl CefDOMDocument {
   // Returns the selection offset within the start node.
   //
   pub fn get_selection_start_offset(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null(){
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -526,8 +507,7 @@ impl CefDOMDocument {
   // Returns the selection offset within the end node.
   //
   pub fn get_selection_end_offset(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null(){
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -542,8 +522,7 @@ impl CefDOMDocument {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_selection_as_markup(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null(){
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -558,8 +537,7 @@ impl CefDOMDocument {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_selection_as_text(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null(){
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -574,8 +552,7 @@ impl CefDOMDocument {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_base_url(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null(){
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -591,8 +568,7 @@ impl CefDOMDocument {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_complete_url(&self, partialURL: &[u16]) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null(){
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -620,8 +596,7 @@ impl CefWrap<*mut cef_domdocument_t> for Option<CefDOMDocument> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_domdocument_t) -> Option<CefDOMDocument> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefDOMDocument::from_c_object_addref(c_object))
@@ -828,8 +803,7 @@ pub struct CefDOMNode {
 impl Clone for CefDOMNode {
   fn clone(&self) -> CefDOMNode{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefDOMNode {
@@ -842,8 +816,7 @@ impl Clone for CefDOMNode {
 impl Drop for CefDOMNode {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -858,8 +831,7 @@ impl CefDOMNode {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_domnode_t) -> CefDOMNode {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefDOMNode {
@@ -873,8 +845,7 @@ impl CefDOMNode {
 
   pub fn c_object_addrefed(&self) -> *mut cef_domnode_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -882,18 +853,17 @@ impl CefDOMNode {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
   // Returns the type for this node.
   //
   pub fn get_type(&self) -> types::cef_dom_node_type_t {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null(){
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -907,8 +877,7 @@ impl CefDOMNode {
   // Returns true (1) if this is a text node.
   //
   pub fn is_text(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null(){
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -922,8 +891,7 @@ impl CefDOMNode {
   // Returns true (1) if this is an element node.
   //
   pub fn is_element(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null(){
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -937,8 +905,7 @@ impl CefDOMNode {
   // Returns true (1) if this is an editable node.
   //
   pub fn is_editable(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null(){
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -952,8 +919,7 @@ impl CefDOMNode {
   // Returns true (1) if this is a form control element node.
   //
   pub fn is_form_control_element(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null(){
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -968,8 +934,7 @@ impl CefDOMNode {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_form_control_element_type(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null(){
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -984,8 +949,7 @@ impl CefDOMNode {
   // object.
   //
   pub fn is_same(&self, that: interfaces::CefDOMNode) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null(){
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1001,8 +965,7 @@ impl CefDOMNode {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_name(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null(){
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1017,8 +980,7 @@ impl CefDOMNode {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_value(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null(){
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1032,8 +994,7 @@ impl CefDOMNode {
   // Set the value of this node. Returns true (1) on success.
   //
   pub fn set_value(&self, value: &[u16]) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null(){
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1049,8 +1010,7 @@ impl CefDOMNode {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_as_markup(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null(){
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1064,8 +1024,7 @@ impl CefDOMNode {
   // Returns the document associated with this node.
   //
   pub fn get_document(&self) -> interfaces::CefDOMDocument {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null(){
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1079,8 +1038,7 @@ impl CefDOMNode {
   // Returns the parent node.
   //
   pub fn get_parent(&self) -> interfaces::CefDOMNode {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null(){
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1094,8 +1052,7 @@ impl CefDOMNode {
   // Returns the previous sibling node.
   //
   pub fn get_previous_sibling(&self) -> interfaces::CefDOMNode {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null(){
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1109,8 +1066,7 @@ impl CefDOMNode {
   // Returns the next sibling node.
   //
   pub fn get_next_sibling(&self) -> interfaces::CefDOMNode {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null(){
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1124,8 +1080,7 @@ impl CefDOMNode {
   // Returns true (1) if this node has child nodes.
   //
   pub fn has_children(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null(){
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1139,8 +1094,7 @@ impl CefDOMNode {
   // Return the first child node.
   //
   pub fn get_first_child(&self) -> interfaces::CefDOMNode {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null(){
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1154,8 +1108,7 @@ impl CefDOMNode {
   // Returns the last child node.
   //
   pub fn get_last_child(&self) -> interfaces::CefDOMNode {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null(){
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1173,8 +1126,7 @@ impl CefDOMNode {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_element_tag_name(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null(){
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1188,8 +1140,7 @@ impl CefDOMNode {
   // Returns true (1) if this element has attributes.
   //
   pub fn has_element_attributes(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null(){
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1203,8 +1154,7 @@ impl CefDOMNode {
   // Returns true (1) if this element has an attribute named |attrName|.
   //
   pub fn has_element_attribute(&self, attrName: &[u16]) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null(){
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1220,8 +1170,7 @@ impl CefDOMNode {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_element_attribute(&self, attrName: &[u16]) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null(){
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1236,8 +1185,7 @@ impl CefDOMNode {
   // Returns a map of all element attributes.
   //
   pub fn get_element_attributes(&self, attrMap: HashMap<String,String>) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null(){
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1254,8 +1202,7 @@ impl CefDOMNode {
   //
   pub fn set_element_attribute(&self, attrName: &[u16],
       value: &[u16]) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null(){
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1272,8 +1219,7 @@ impl CefDOMNode {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_element_inner_text(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null(){
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1300,8 +1246,7 @@ impl CefWrap<*mut cef_domnode_t> for Option<CefDOMNode> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_domnode_t) -> Option<CefDOMNode> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefDOMNode::from_c_object_addref(c_object))
diff --git a/ports/cef/interfaces/cef_download_handler.rs b/ports/cef/interfaces/cef_download_handler.rs
index 7dce76b2ae0..143e2fe27c4 100644
--- a/ports/cef/interfaces/cef_download_handler.rs
+++ b/ports/cef/interfaces/cef_download_handler.rs
@@ -90,8 +90,7 @@ pub struct CefBeforeDownloadCallback {
 impl Clone for CefBeforeDownloadCallback {
   fn clone(&self) -> CefBeforeDownloadCallback{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefBeforeDownloadCallback {
@@ -104,8 +103,7 @@ impl Clone for CefBeforeDownloadCallback {
 impl Drop for CefBeforeDownloadCallback {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -120,8 +118,7 @@ impl CefBeforeDownloadCallback {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_before_download_callback_t) -> CefBeforeDownloadCallback {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefBeforeDownloadCallback {
@@ -135,8 +132,7 @@ impl CefBeforeDownloadCallback {
 
   pub fn c_object_addrefed(&self) -> *mut cef_before_download_callback_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -144,10 +140,10 @@ impl CefBeforeDownloadCallback {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -157,8 +153,7 @@ impl CefBeforeDownloadCallback {
   // (1) if you do wish to show the default "Save As" dialog.
   //
   pub fn cont(&self, download_path: &[u16], show_dialog: libc::c_int) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -187,8 +182,7 @@ impl CefWrap<*mut cef_before_download_callback_t> for Option<CefBeforeDownloadCa
     }
   }
   unsafe fn to_rust(c_object: *mut cef_before_download_callback_t) -> Option<CefBeforeDownloadCallback> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefBeforeDownloadCallback::from_c_object_addref(c_object))
@@ -249,8 +243,7 @@ pub struct CefDownloadItemCallback {
 impl Clone for CefDownloadItemCallback {
   fn clone(&self) -> CefDownloadItemCallback{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefDownloadItemCallback {
@@ -263,8 +256,7 @@ impl Clone for CefDownloadItemCallback {
 impl Drop for CefDownloadItemCallback {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -279,8 +271,7 @@ impl CefDownloadItemCallback {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_download_item_callback_t) -> CefDownloadItemCallback {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefDownloadItemCallback {
@@ -294,8 +285,7 @@ impl CefDownloadItemCallback {
 
   pub fn c_object_addrefed(&self) -> *mut cef_download_item_callback_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -303,18 +293,17 @@ impl CefDownloadItemCallback {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
   // Call to cancel the download.
   //
   pub fn cancel(&self) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -328,8 +317,7 @@ impl CefDownloadItemCallback {
   // Call to pause the download.
   //
   pub fn pause(&self) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -343,8 +331,7 @@ impl CefDownloadItemCallback {
   // Call to resume the download.
   //
   pub fn resume(&self) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -371,8 +358,7 @@ impl CefWrap<*mut cef_download_item_callback_t> for Option<CefDownloadItemCallba
     }
   }
   unsafe fn to_rust(c_object: *mut cef_download_item_callback_t) -> Option<CefDownloadItemCallback> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefDownloadItemCallback::from_c_object_addref(c_object))
@@ -444,8 +430,7 @@ pub struct CefDownloadHandler {
 impl Clone for CefDownloadHandler {
   fn clone(&self) -> CefDownloadHandler{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefDownloadHandler {
@@ -458,8 +443,7 @@ impl Clone for CefDownloadHandler {
 impl Drop for CefDownloadHandler {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -474,8 +458,7 @@ impl CefDownloadHandler {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_download_handler_t) -> CefDownloadHandler {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefDownloadHandler {
@@ -489,8 +472,7 @@ impl CefDownloadHandler {
 
   pub fn c_object_addrefed(&self) -> *mut cef_download_handler_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -498,10 +480,10 @@ impl CefDownloadHandler {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -514,8 +496,7 @@ impl CefDownloadHandler {
   pub fn on_before_download(&self, browser: interfaces::CefBrowser,
       download_item: interfaces::CefDownloadItem, suggested_name: &[u16],
       callback: interfaces::CefBeforeDownloadCallback) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -539,8 +520,7 @@ impl CefDownloadHandler {
   pub fn on_download_updated(&self, browser: interfaces::CefBrowser,
       download_item: interfaces::CefDownloadItem,
       callback: interfaces::CefDownloadItemCallback) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -570,8 +550,7 @@ impl CefWrap<*mut cef_download_handler_t> for Option<CefDownloadHandler> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_download_handler_t) -> Option<CefDownloadHandler> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefDownloadHandler::from_c_object_addref(c_object))
diff --git a/ports/cef/interfaces/cef_download_item.rs b/ports/cef/interfaces/cef_download_item.rs
index 88ca0fc16d9..93062f3555f 100644
--- a/ports/cef/interfaces/cef_download_item.rs
+++ b/ports/cef/interfaces/cef_download_item.rs
@@ -189,8 +189,7 @@ pub struct CefDownloadItem {
 impl Clone for CefDownloadItem {
   fn clone(&self) -> CefDownloadItem{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefDownloadItem {
@@ -203,8 +202,7 @@ impl Clone for CefDownloadItem {
 impl Drop for CefDownloadItem {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -219,8 +217,7 @@ impl CefDownloadItem {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_download_item_t) -> CefDownloadItem {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefDownloadItem {
@@ -234,8 +231,7 @@ impl CefDownloadItem {
 
   pub fn c_object_addrefed(&self) -> *mut cef_download_item_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -243,10 +239,10 @@ impl CefDownloadItem {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -254,8 +250,7 @@ impl CefDownloadItem {
   // if this function returns false (0).
   //
   pub fn is_valid(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -269,8 +264,7 @@ impl CefDownloadItem {
   // Returns true (1) if the download is in progress.
   //
   pub fn is_in_progress(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -284,8 +278,7 @@ impl CefDownloadItem {
   // Returns true (1) if the download is complete.
   //
   pub fn is_complete(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -299,8 +292,7 @@ impl CefDownloadItem {
   // Returns true (1) if the download has been canceled or interrupted.
   //
   pub fn is_canceled(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -314,8 +306,7 @@ impl CefDownloadItem {
   // Returns a simple speed estimate in bytes/s.
   //
   pub fn get_current_speed(&self) -> i64 {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -330,8 +321,7 @@ impl CefDownloadItem {
   // unknown.
   //
   pub fn get_percent_complete(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -345,8 +335,7 @@ impl CefDownloadItem {
   // Returns the total number of bytes.
   //
   pub fn get_total_bytes(&self) -> i64 {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -360,8 +349,7 @@ impl CefDownloadItem {
   // Returns the number of received bytes.
   //
   pub fn get_received_bytes(&self) -> i64 {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -375,8 +363,7 @@ impl CefDownloadItem {
   // Returns the time that the download started.
   //
   pub fn get_start_time(&self) -> types::cef_time_t {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -390,8 +377,7 @@ impl CefDownloadItem {
   // Returns the time that the download ended.
   //
   pub fn get_end_time(&self) -> types::cef_time_t {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -406,8 +392,7 @@ impl CefDownloadItem {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_full_path(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -421,8 +406,7 @@ impl CefDownloadItem {
   // Returns the unique identifier for this download.
   //
   pub fn get_id(&self) -> u32 {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -437,8 +421,7 @@ impl CefDownloadItem {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_url(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -453,8 +436,7 @@ impl CefDownloadItem {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_original_url(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -469,8 +451,7 @@ impl CefDownloadItem {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_suggested_file_name(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -485,8 +466,7 @@ impl CefDownloadItem {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_content_disposition(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -501,8 +481,7 @@ impl CefDownloadItem {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_mime_type(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -529,8 +508,7 @@ impl CefWrap<*mut cef_download_item_t> for Option<CefDownloadItem> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_download_item_t) -> Option<CefDownloadItem> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefDownloadItem::from_c_object_addref(c_object))
diff --git a/ports/cef/interfaces/cef_drag_data.rs b/ports/cef/interfaces/cef_drag_data.rs
index eefaa1f2374..397996083e5 100644
--- a/ports/cef/interfaces/cef_drag_data.rs
+++ b/ports/cef/interfaces/cef_drag_data.rs
@@ -227,8 +227,7 @@ pub struct CefDragData {
 impl Clone for CefDragData {
   fn clone(&self) -> CefDragData{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefDragData {
@@ -241,8 +240,7 @@ impl Clone for CefDragData {
 impl Drop for CefDragData {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -257,8 +255,7 @@ impl CefDragData {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_drag_data_t) -> CefDragData {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefDragData {
@@ -272,8 +269,7 @@ impl CefDragData {
 
   pub fn c_object_addrefed(&self) -> *mut cef_drag_data_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -281,18 +277,17 @@ impl CefDragData {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
   // Returns a copy of the current object.
   //
   pub fn clone(&self) -> interfaces::CefDragData {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -306,8 +301,7 @@ impl CefDragData {
   // Returns true (1) if this object is read-only.
   //
   pub fn is_read_only(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -321,8 +315,7 @@ impl CefDragData {
   // Returns true (1) if the drag data is a link.
   //
   pub fn is_link(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -336,8 +329,7 @@ impl CefDragData {
   // Returns true (1) if the drag data is a text or html fragment.
   //
   pub fn is_fragment(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -351,8 +343,7 @@ impl CefDragData {
   // Returns true (1) if the drag data is a file.
   //
   pub fn is_file(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -367,8 +358,7 @@ impl CefDragData {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_link_url(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -383,8 +373,7 @@ impl CefDragData {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_link_title(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -399,8 +388,7 @@ impl CefDragData {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_link_metadata(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -415,8 +403,7 @@ impl CefDragData {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_fragment_text(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -431,8 +418,7 @@ impl CefDragData {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_fragment_html(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -448,8 +434,7 @@ impl CefDragData {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_fragment_base_url(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -464,8 +449,7 @@ impl CefDragData {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_file_name(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -483,8 +467,7 @@ impl CefDragData {
   //
   pub fn get_file_contents(&self,
       writer: interfaces::CefStreamWriter) -> libc::size_t {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -500,8 +483,7 @@ impl CefDragData {
   // window.
   //
   pub fn get_file_names(&self, names: &Vec<String>) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -516,8 +498,7 @@ impl CefDragData {
   // Set the link URL that is being dragged.
   //
   pub fn set_link_url(&self, url: &[u16]) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -532,8 +513,7 @@ impl CefDragData {
   // Set the title associated with the link being dragged.
   //
   pub fn set_link_title(&self, title: &[u16]) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -548,8 +528,7 @@ impl CefDragData {
   // Set the metadata associated with the link being dragged.
   //
   pub fn set_link_metadata(&self, data: &[u16]) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -564,8 +543,7 @@ impl CefDragData {
   // Set the plain text fragment that is being dragged.
   //
   pub fn set_fragment_text(&self, text: &[u16]) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -580,8 +558,7 @@ impl CefDragData {
   // Set the text/html fragment that is being dragged.
   //
   pub fn set_fragment_html(&self, html: &[u16]) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -596,8 +573,7 @@ impl CefDragData {
   // Set the base URL that the fragment came from.
   //
   pub fn set_fragment_base_url(&self, base_url: &[u16]) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -614,8 +590,7 @@ impl CefDragData {
   // to drag in this kind of data.
   //
   pub fn reset_file_contents(&self) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -629,8 +604,7 @@ impl CefDragData {
   // Add a file that is being dragged into the webview.
   //
   pub fn add_file(&self, path: &[u16], display_name: &[u16]) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -670,8 +644,7 @@ impl CefWrap<*mut cef_drag_data_t> for Option<CefDragData> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_drag_data_t) -> Option<CefDragData> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefDragData::from_c_object_addref(c_object))
diff --git a/ports/cef/interfaces/cef_drag_handler.rs b/ports/cef/interfaces/cef_drag_handler.rs
index 472aad9948b..6697ac1d434 100644
--- a/ports/cef/interfaces/cef_drag_handler.rs
+++ b/ports/cef/interfaces/cef_drag_handler.rs
@@ -105,8 +105,7 @@ pub struct CefDragHandler {
 impl Clone for CefDragHandler {
   fn clone(&self) -> CefDragHandler{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefDragHandler {
@@ -119,8 +118,7 @@ impl Clone for CefDragHandler {
 impl Drop for CefDragHandler {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -135,8 +133,7 @@ impl CefDragHandler {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_drag_handler_t) -> CefDragHandler {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefDragHandler {
@@ -150,8 +147,7 @@ impl CefDragHandler {
 
   pub fn c_object_addrefed(&self) -> *mut cef_drag_handler_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -159,10 +155,10 @@ impl CefDragHandler {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -174,8 +170,7 @@ impl CefDragHandler {
   pub fn on_drag_enter(&self, browser: interfaces::CefBrowser,
       dragData: interfaces::CefDragData,
       mask: types::cef_drag_operations_mask_t) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -198,8 +193,7 @@ impl CefDragHandler {
   pub fn on_draggable_regions_changed(&self, browser: interfaces::CefBrowser,
       regions_count: libc::size_t,
       regions: *const types::cef_draggable_region_t) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -229,8 +223,7 @@ impl CefWrap<*mut cef_drag_handler_t> for Option<CefDragHandler> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_drag_handler_t) -> Option<CefDragHandler> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefDragHandler::from_c_object_addref(c_object))
diff --git a/ports/cef/interfaces/cef_find_handler.rs b/ports/cef/interfaces/cef_find_handler.rs
index 05155095451..46f17d09989 100644
--- a/ports/cef/interfaces/cef_find_handler.rs
+++ b/ports/cef/interfaces/cef_find_handler.rs
@@ -95,8 +95,7 @@ pub struct CefFindHandler {
 impl Clone for CefFindHandler {
   fn clone(&self) -> CefFindHandler{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefFindHandler {
@@ -109,8 +108,7 @@ impl Clone for CefFindHandler {
 impl Drop for CefFindHandler {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -125,8 +123,7 @@ impl CefFindHandler {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_find_handler_t) -> CefFindHandler {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefFindHandler {
@@ -140,8 +137,7 @@ impl CefFindHandler {
 
   pub fn c_object_addrefed(&self) -> *mut cef_find_handler_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -149,10 +145,10 @@ impl CefFindHandler {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -167,8 +163,7 @@ impl CefFindHandler {
       identifier: libc::c_int, count: libc::c_int,
       selectionRect: &types::cef_rect_t, activeMatchOrdinal: libc::c_int,
       finalUpdate: libc::c_int) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -201,8 +196,7 @@ impl CefWrap<*mut cef_find_handler_t> for Option<CefFindHandler> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_find_handler_t) -> Option<CefFindHandler> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefFindHandler::from_c_object_addref(c_object))
diff --git a/ports/cef/interfaces/cef_focus_handler.rs b/ports/cef/interfaces/cef_focus_handler.rs
index b5d1d6072b0..6d0ba851655 100644
--- a/ports/cef/interfaces/cef_focus_handler.rs
+++ b/ports/cef/interfaces/cef_focus_handler.rs
@@ -106,8 +106,7 @@ pub struct CefFocusHandler {
 impl Clone for CefFocusHandler {
   fn clone(&self) -> CefFocusHandler{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefFocusHandler {
@@ -120,8 +119,7 @@ impl Clone for CefFocusHandler {
 impl Drop for CefFocusHandler {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -136,8 +134,7 @@ impl CefFocusHandler {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_focus_handler_t) -> CefFocusHandler {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefFocusHandler {
@@ -151,8 +148,7 @@ impl CefFocusHandler {
 
   pub fn c_object_addrefed(&self) -> *mut cef_focus_handler_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -160,10 +156,10 @@ impl CefFocusHandler {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -174,8 +170,7 @@ impl CefFocusHandler {
   //
   pub fn on_take_focus(&self, browser: interfaces::CefBrowser,
       next: libc::c_int) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -194,8 +189,7 @@ impl CefFocusHandler {
   //
   pub fn on_set_focus(&self, browser: interfaces::CefBrowser,
       source: types::cef_focus_source_t) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -211,8 +205,7 @@ impl CefFocusHandler {
   // Called when the browser component has received focus.
   //
   pub fn on_got_focus(&self, browser: interfaces::CefBrowser) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -240,8 +233,7 @@ impl CefWrap<*mut cef_focus_handler_t> for Option<CefFocusHandler> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_focus_handler_t) -> Option<CefFocusHandler> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefFocusHandler::from_c_object_addref(c_object))
diff --git a/ports/cef/interfaces/cef_frame.rs b/ports/cef/interfaces/cef_frame.rs
index 62fa1bb8d0e..f956d4d19ab 100644
--- a/ports/cef/interfaces/cef_frame.rs
+++ b/ports/cef/interfaces/cef_frame.rs
@@ -239,8 +239,7 @@ pub struct CefFrame {
 impl Clone for CefFrame {
   fn clone(&self) -> CefFrame{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefFrame {
@@ -253,8 +252,7 @@ impl Clone for CefFrame {
 impl Drop for CefFrame {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -269,8 +267,7 @@ impl CefFrame {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_frame_t) -> CefFrame {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefFrame {
@@ -284,8 +281,7 @@ impl CefFrame {
 
   pub fn c_object_addrefed(&self) -> *mut cef_frame_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -293,18 +289,17 @@ impl CefFrame {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
   // True if this object is currently attached to a valid frame.
   //
   pub fn is_valid(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -318,8 +313,7 @@ impl CefFrame {
   // Execute undo in this frame.
   //
   pub fn undo(&self) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -333,8 +327,7 @@ impl CefFrame {
   // Execute redo in this frame.
   //
   pub fn redo(&self) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -348,8 +341,7 @@ impl CefFrame {
   // Execute cut in this frame.
   //
   pub fn cut(&self) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -363,8 +355,7 @@ impl CefFrame {
   // Execute copy in this frame.
   //
   pub fn copy(&self) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -378,8 +369,7 @@ impl CefFrame {
   // Execute paste in this frame.
   //
   pub fn paste(&self) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -393,8 +383,7 @@ impl CefFrame {
   // Execute delete in this frame.
   //
   pub fn del(&self) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -408,8 +397,7 @@ impl CefFrame {
   // Execute select all in this frame.
   //
   pub fn select_all(&self) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -425,8 +413,7 @@ impl CefFrame {
   // browser process.
   //
   pub fn view_source(&self) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -441,8 +428,7 @@ impl CefFrame {
   // visitor.
   //
   pub fn get_source(&self, visitor: interfaces::CefStringVisitor) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -458,8 +444,7 @@ impl CefFrame {
   // visitor.
   //
   pub fn get_text(&self, visitor: interfaces::CefStringVisitor) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -474,8 +459,7 @@ impl CefFrame {
   // Load the request represented by the |request| object.
   //
   pub fn load_request(&self, request: interfaces::CefRequest) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -490,8 +474,7 @@ impl CefFrame {
   // Load the specified |url|.
   //
   pub fn load_url(&self, url: &[u16]) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -508,8 +491,7 @@ impl CefFrame {
   // link clicks and web security restrictions may not behave as expected.
   //
   pub fn load_string(&self, string_val: &[u16], url: &[u16]) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -530,8 +512,7 @@ impl CefFrame {
   //
   pub fn execute_java_script(&self, code: &[u16], script_url: &[u16],
       start_line: libc::c_int) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -548,8 +529,7 @@ impl CefFrame {
   // Returns true (1) if this is the main (top-level) frame.
   //
   pub fn is_main(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -563,8 +543,7 @@ impl CefFrame {
   // Returns true (1) if this is the focused frame.
   //
   pub fn is_focused(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -583,8 +562,7 @@ impl CefFrame {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_name(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -598,8 +576,7 @@ impl CefFrame {
   // Returns the globally unique identifier for this frame.
   //
   pub fn get_identifier(&self) -> i64 {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -614,8 +591,7 @@ impl CefFrame {
   // frame.
   //
   pub fn get_parent(&self) -> interfaces::CefFrame {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -630,8 +606,7 @@ impl CefFrame {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_url(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -645,8 +620,7 @@ impl CefFrame {
   // Returns the browser that this frame belongs to.
   //
   pub fn get_browser(&self) -> interfaces::CefBrowser {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -661,8 +635,7 @@ impl CefFrame {
   // called from the render process.
   //
   pub fn get_v8context(&self) -> interfaces::CefV8Context {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -677,8 +650,7 @@ impl CefFrame {
   // process.
   //
   pub fn visit_dom(&self, visitor: interfaces::CefDOMVisitor) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -706,8 +678,7 @@ impl CefWrap<*mut cef_frame_t> for Option<CefFrame> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_frame_t) -> Option<CefFrame> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefFrame::from_c_object_addref(c_object))
diff --git a/ports/cef/interfaces/cef_geolocation.rs b/ports/cef/interfaces/cef_geolocation.rs
index 0b4b54a3daa..f9d9fecfbc2 100644
--- a/ports/cef/interfaces/cef_geolocation.rs
+++ b/ports/cef/interfaces/cef_geolocation.rs
@@ -90,8 +90,7 @@ pub struct CefGetGeolocationCallback {
 impl Clone for CefGetGeolocationCallback {
   fn clone(&self) -> CefGetGeolocationCallback{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefGetGeolocationCallback {
@@ -104,8 +103,7 @@ impl Clone for CefGetGeolocationCallback {
 impl Drop for CefGetGeolocationCallback {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -120,8 +118,7 @@ impl CefGetGeolocationCallback {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_get_geolocation_callback_t) -> CefGetGeolocationCallback {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefGetGeolocationCallback {
@@ -135,8 +132,7 @@ impl CefGetGeolocationCallback {
 
   pub fn c_object_addrefed(&self) -> *mut cef_get_geolocation_callback_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -144,10 +140,10 @@ impl CefGetGeolocationCallback {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -156,8 +152,7 @@ impl CefGetGeolocationCallback {
   //
   pub fn on_location_update(&self, position: &interfaces::CefGeoposition) -> (
       ) {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -185,8 +180,7 @@ impl CefWrap<*mut cef_get_geolocation_callback_t> for Option<CefGetGeolocationCa
     }
   }
   unsafe fn to_rust(c_object: *mut cef_get_geolocation_callback_t) -> Option<CefGetGeolocationCallback> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefGetGeolocationCallback::from_c_object_addref(c_object))
diff --git a/ports/cef/interfaces/cef_geolocation_handler.rs b/ports/cef/interfaces/cef_geolocation_handler.rs
index 5214a245c51..9d75a01ab29 100644
--- a/ports/cef/interfaces/cef_geolocation_handler.rs
+++ b/ports/cef/interfaces/cef_geolocation_handler.rs
@@ -88,8 +88,7 @@ pub struct CefGeolocationCallback {
 impl Clone for CefGeolocationCallback {
   fn clone(&self) -> CefGeolocationCallback{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefGeolocationCallback {
@@ -102,8 +101,7 @@ impl Clone for CefGeolocationCallback {
 impl Drop for CefGeolocationCallback {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -118,8 +116,7 @@ impl CefGeolocationCallback {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_geolocation_callback_t) -> CefGeolocationCallback {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefGeolocationCallback {
@@ -133,8 +130,7 @@ impl CefGeolocationCallback {
 
   pub fn c_object_addrefed(&self) -> *mut cef_geolocation_callback_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -142,18 +138,17 @@ impl CefGeolocationCallback {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
   // Call to allow or deny geolocation access.
   //
   pub fn cont(&self, allow: libc::c_int) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null(){
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -181,8 +176,7 @@ impl CefWrap<*mut cef_geolocation_callback_t> for Option<CefGeolocationCallback>
     }
   }
   unsafe fn to_rust(c_object: *mut cef_geolocation_callback_t) -> Option<CefGeolocationCallback> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefGeolocationCallback::from_c_object_addref(c_object))
@@ -254,8 +248,7 @@ pub struct CefGeolocationHandler {
 impl Clone for CefGeolocationHandler {
   fn clone(&self) -> CefGeolocationHandler{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefGeolocationHandler {
@@ -268,8 +261,7 @@ impl Clone for CefGeolocationHandler {
 impl Drop for CefGeolocationHandler {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -284,8 +276,7 @@ impl CefGeolocationHandler {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_geolocation_handler_t) -> CefGeolocationHandler {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefGeolocationHandler {
@@ -299,8 +290,7 @@ impl CefGeolocationHandler {
 
   pub fn c_object_addrefed(&self) -> *mut cef_geolocation_handler_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -308,10 +298,10 @@ impl CefGeolocationHandler {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -326,8 +316,7 @@ impl CefGeolocationHandler {
       browser: interfaces::CefBrowser, requesting_url: &[u16],
       request_id: libc::c_int,
       callback: interfaces::CefGeolocationCallback) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null(){
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -349,8 +338,7 @@ impl CefGeolocationHandler {
   pub fn on_cancel_geolocation_permission(&self,
       browser: interfaces::CefBrowser, requesting_url: &[u16],
       request_id: libc::c_int) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null(){
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -380,8 +368,7 @@ impl CefWrap<*mut cef_geolocation_handler_t> for Option<CefGeolocationHandler> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_geolocation_handler_t) -> Option<CefGeolocationHandler> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefGeolocationHandler::from_c_object_addref(c_object))
diff --git a/ports/cef/interfaces/cef_jsdialog_handler.rs b/ports/cef/interfaces/cef_jsdialog_handler.rs
index bdb24eb6abb..13edb21fbc5 100644
--- a/ports/cef/interfaces/cef_jsdialog_handler.rs
+++ b/ports/cef/interfaces/cef_jsdialog_handler.rs
@@ -89,8 +89,7 @@ pub struct CefJSDialogCallback {
 impl Clone for CefJSDialogCallback {
   fn clone(&self) -> CefJSDialogCallback{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefJSDialogCallback {
@@ -103,8 +102,7 @@ impl Clone for CefJSDialogCallback {
 impl Drop for CefJSDialogCallback {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -119,8 +117,7 @@ impl CefJSDialogCallback {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_jsdialog_callback_t) -> CefJSDialogCallback {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefJSDialogCallback {
@@ -134,8 +131,7 @@ impl CefJSDialogCallback {
 
   pub fn c_object_addrefed(&self) -> *mut cef_jsdialog_callback_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -143,10 +139,10 @@ impl CefJSDialogCallback {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -154,8 +150,7 @@ impl CefJSDialogCallback {
   // was pressed. The |user_input| value should be specified for prompt dialogs.
   //
   pub fn cont(&self, success: libc::c_int, user_input: &[u16]) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -184,8 +179,7 @@ impl CefWrap<*mut cef_jsdialog_callback_t> for Option<CefJSDialogCallback> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_jsdialog_callback_t) -> Option<CefJSDialogCallback> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefJSDialogCallback::from_c_object_addref(c_object))
@@ -284,8 +278,7 @@ pub struct CefJSDialogHandler {
 impl Clone for CefJSDialogHandler {
   fn clone(&self) -> CefJSDialogHandler{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefJSDialogHandler {
@@ -298,8 +291,7 @@ impl Clone for CefJSDialogHandler {
 impl Drop for CefJSDialogHandler {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -314,8 +306,7 @@ impl CefJSDialogHandler {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_jsdialog_handler_t) -> CefJSDialogHandler {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefJSDialogHandler {
@@ -329,8 +320,7 @@ impl CefJSDialogHandler {
 
   pub fn c_object_addrefed(&self) -> *mut cef_jsdialog_handler_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -338,10 +328,10 @@ impl CefJSDialogHandler {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -364,8 +354,7 @@ impl CefJSDialogHandler {
       message_text: &[u16], default_prompt_text: &[u16],
       callback: interfaces::CefJSDialogCallback,
       suppress_message: &mut libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -394,8 +383,7 @@ impl CefJSDialogHandler {
   pub fn on_before_unload_dialog(&self, browser: interfaces::CefBrowser,
       message_text: &[u16], is_reload: libc::c_int,
       callback: interfaces::CefJSDialogCallback) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -415,8 +403,7 @@ impl CefJSDialogHandler {
   // dialogs are currently pending.
   //
   pub fn on_reset_dialog_state(&self, browser: interfaces::CefBrowser) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -431,8 +418,7 @@ impl CefJSDialogHandler {
   // Called when the default implementation dialog is closed.
   //
   pub fn on_dialog_closed(&self, browser: interfaces::CefBrowser) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -460,8 +446,7 @@ impl CefWrap<*mut cef_jsdialog_handler_t> for Option<CefJSDialogHandler> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_jsdialog_handler_t) -> Option<CefJSDialogHandler> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefJSDialogHandler::from_c_object_addref(c_object))
diff --git a/ports/cef/interfaces/cef_keyboard_handler.rs b/ports/cef/interfaces/cef_keyboard_handler.rs
index 88cf4f2a02b..67ec12c5cbe 100644
--- a/ports/cef/interfaces/cef_keyboard_handler.rs
+++ b/ports/cef/interfaces/cef_keyboard_handler.rs
@@ -104,8 +104,7 @@ pub struct CefKeyboardHandler {
 impl Clone for CefKeyboardHandler {
   fn clone(&self) -> CefKeyboardHandler{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefKeyboardHandler {
@@ -118,8 +117,7 @@ impl Clone for CefKeyboardHandler {
 impl Drop for CefKeyboardHandler {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -134,8 +132,7 @@ impl CefKeyboardHandler {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_keyboard_handler_t) -> CefKeyboardHandler {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefKeyboardHandler {
@@ -149,8 +146,7 @@ impl CefKeyboardHandler {
 
   pub fn c_object_addrefed(&self) -> *mut cef_keyboard_handler_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -158,10 +154,10 @@ impl CefKeyboardHandler {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   // Called before a keyboard event is sent to the renderer. |event| contains
@@ -172,8 +168,7 @@ impl CefKeyboardHandler {
   pub fn on_pre_key_event(&self, browser: interfaces::CefBrowser,
       event: &interfaces::CefKeyEvent, os_event: types::cef_event_handle_t,
       is_keyboard_shortcut: &mut libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -196,8 +191,7 @@ impl CefKeyboardHandler {
   pub fn on_key_event(&self, browser: interfaces::CefBrowser,
       event: &interfaces::CefKeyEvent,
       os_event: types::cef_event_handle_t) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -227,8 +221,7 @@ impl CefWrap<*mut cef_keyboard_handler_t> for Option<CefKeyboardHandler> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_keyboard_handler_t) -> Option<CefKeyboardHandler> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefKeyboardHandler::from_c_object_addref(c_object))
diff --git a/ports/cef/interfaces/cef_life_span_handler.rs b/ports/cef/interfaces/cef_life_span_handler.rs
index cf2da948869..926bfd1ec39 100644
--- a/ports/cef/interfaces/cef_life_span_handler.rs
+++ b/ports/cef/interfaces/cef_life_span_handler.rs
@@ -199,8 +199,7 @@ pub struct CefLifeSpanHandler {
 impl Clone for CefLifeSpanHandler {
   fn clone(&self) -> CefLifeSpanHandler{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefLifeSpanHandler {
@@ -213,8 +212,7 @@ impl Clone for CefLifeSpanHandler {
 impl Drop for CefLifeSpanHandler {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -229,8 +227,7 @@ impl CefLifeSpanHandler {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_life_span_handler_t) -> CefLifeSpanHandler {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefLifeSpanHandler {
@@ -244,8 +241,7 @@ impl CefLifeSpanHandler {
 
   pub fn c_object_addrefed(&self) -> *mut cef_life_span_handler_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -253,10 +249,10 @@ impl CefLifeSpanHandler {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -285,8 +281,7 @@ impl CefLifeSpanHandler {
       client: interfaces::CefClient,
       settings: &mut interfaces::CefBrowserSettings,
       no_javascript_access: &mut libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -311,8 +306,7 @@ impl CefLifeSpanHandler {
   // Called after a new browser is created.
   //
   pub fn on_after_created(&self, browser: interfaces::CefBrowser) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -329,8 +323,7 @@ impl CefLifeSpanHandler {
   // implementation or true (1) to use a custom implementation.
   //
   pub fn run_modal(&self, browser: interfaces::CefBrowser) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -399,8 +392,7 @@ impl CefLifeSpanHandler {
   //     exist.
   //
   pub fn do_close(&self, browser: interfaces::CefBrowser) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -420,8 +412,7 @@ impl CefLifeSpanHandler {
   // additional usage information.
   //
   pub fn on_before_close(&self, browser: interfaces::CefBrowser) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -449,8 +440,7 @@ impl CefWrap<*mut cef_life_span_handler_t> for Option<CefLifeSpanHandler> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_life_span_handler_t) -> Option<CefLifeSpanHandler> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefLifeSpanHandler::from_c_object_addref(c_object))
diff --git a/ports/cef/interfaces/cef_load_handler.rs b/ports/cef/interfaces/cef_load_handler.rs
index d18a0ec3930..2eca524acc6 100644
--- a/ports/cef/interfaces/cef_load_handler.rs
+++ b/ports/cef/interfaces/cef_load_handler.rs
@@ -132,8 +132,7 @@ pub struct CefLoadHandler {
 impl Clone for CefLoadHandler {
   fn clone(&self) -> CefLoadHandler{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefLoadHandler {
@@ -146,8 +145,7 @@ impl Clone for CefLoadHandler {
 impl Drop for CefLoadHandler {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -162,8 +160,7 @@ impl CefLoadHandler {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_load_handler_t) -> CefLoadHandler {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefLoadHandler {
@@ -177,8 +174,7 @@ impl CefLoadHandler {
 
   pub fn c_object_addrefed(&self) -> *mut cef_load_handler_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -186,10 +182,10 @@ impl CefLoadHandler {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -201,8 +197,7 @@ impl CefLoadHandler {
   pub fn on_loading_state_change(&self, browser: interfaces::CefBrowser,
       isLoading: libc::c_int, canGoBack: libc::c_int,
       canGoForward: libc::c_int) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -227,8 +222,7 @@ impl CefLoadHandler {
   //
   pub fn on_load_start(&self, browser: interfaces::CefBrowser,
       frame: interfaces::CefFrame) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -250,8 +244,7 @@ impl CefLoadHandler {
   //
   pub fn on_load_end(&self, browser: interfaces::CefBrowser,
       frame: interfaces::CefFrame, httpStatusCode: libc::c_int) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -273,8 +266,7 @@ impl CefLoadHandler {
   pub fn on_load_error(&self, browser: interfaces::CefBrowser,
       frame: interfaces::CefFrame, errorCode: types::cef_errorcode_t,
       errorText: &[u16], failedUrl: &[u16]) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -306,8 +298,7 @@ impl CefWrap<*mut cef_load_handler_t> for Option<CefLoadHandler> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_load_handler_t) -> Option<CefLoadHandler> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefLoadHandler::from_c_object_addref(c_object))
diff --git a/ports/cef/interfaces/cef_menu_model.rs b/ports/cef/interfaces/cef_menu_model.rs
index 2c686f47576..c8cdf7c4c89 100644
--- a/ports/cef/interfaces/cef_menu_model.rs
+++ b/ports/cef/interfaces/cef_menu_model.rs
@@ -426,8 +426,7 @@ pub struct CefMenuModel {
 impl Clone for CefMenuModel {
   fn clone(&self) -> CefMenuModel{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefMenuModel {
@@ -440,8 +439,7 @@ impl Clone for CefMenuModel {
 impl Drop for CefMenuModel {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -456,8 +454,7 @@ impl CefMenuModel {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_menu_model_t) -> CefMenuModel {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefMenuModel {
@@ -471,8 +468,7 @@ impl CefMenuModel {
 
   pub fn c_object_addrefed(&self) -> *mut cef_menu_model_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -480,18 +476,17 @@ impl CefMenuModel {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
   // Clears the menu. Returns true (1) on success.
   //
   pub fn clear(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -505,8 +500,7 @@ impl CefMenuModel {
   // Returns the number of items in this menu.
   //
   pub fn get_count(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -520,8 +514,7 @@ impl CefMenuModel {
   // Add a separator to the menu. Returns true (1) on success.
   //
   pub fn add_separator(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -536,8 +529,7 @@ impl CefMenuModel {
   //
   pub fn add_item(&self, command_id: libc::c_int,
       label: &[u16]) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -554,8 +546,7 @@ impl CefMenuModel {
   //
   pub fn add_check_item(&self, command_id: libc::c_int,
       label: &[u16]) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -573,8 +564,7 @@ impl CefMenuModel {
   //
   pub fn add_radio_item(&self, command_id: libc::c_int, label: &[u16],
       group_id: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -592,8 +582,7 @@ impl CefMenuModel {
   //
   pub fn add_sub_menu(&self, command_id: libc::c_int,
       label: &[u16]) -> interfaces::CefMenuModel {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -610,8 +599,7 @@ impl CefMenuModel {
   // on success.
   //
   pub fn insert_separator_at(&self, index: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -628,8 +616,7 @@ impl CefMenuModel {
   //
   pub fn insert_item_at(&self, index: libc::c_int, command_id: libc::c_int,
       label: &[u16]) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -648,8 +635,7 @@ impl CefMenuModel {
   //
   pub fn insert_check_item_at(&self, index: libc::c_int,
       command_id: libc::c_int, label: &[u16]) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -670,8 +656,7 @@ impl CefMenuModel {
   pub fn insert_radio_item_at(&self, index: libc::c_int,
       command_id: libc::c_int, label: &[u16],
       group_id: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -691,8 +676,7 @@ impl CefMenuModel {
   //
   pub fn insert_sub_menu_at(&self, index: libc::c_int, command_id: libc::c_int,
       label: &[u16]) -> interfaces::CefMenuModel {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -710,8 +694,7 @@ impl CefMenuModel {
   // success.
   //
   pub fn remove(&self, command_id: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -726,8 +709,7 @@ impl CefMenuModel {
   // Removes the item at the specified |index|. Returns true (1) on success.
   //
   pub fn remove_at(&self, index: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -743,8 +725,7 @@ impl CefMenuModel {
   // found due to the command id not existing in the menu.
   //
   pub fn get_index_of(&self, command_id: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -760,8 +741,7 @@ impl CefMenuModel {
   // invalid range or the index being a separator.
   //
   pub fn get_command_id_at(&self, index: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -777,8 +757,7 @@ impl CefMenuModel {
   //
   pub fn set_command_id_at(&self, index: libc::c_int,
       command_id: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -795,8 +774,7 @@ impl CefMenuModel {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_label(&self, command_id: libc::c_int) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -813,8 +791,7 @@ impl CefMenuModel {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_label_at(&self, index: libc::c_int) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -830,8 +807,7 @@ impl CefMenuModel {
   //
   pub fn set_label(&self, command_id: libc::c_int,
       label: &[u16]) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -847,8 +823,7 @@ impl CefMenuModel {
   // Set the label at the specified |index|. Returns true (1) on success.
   //
   pub fn set_label_at(&self, index: libc::c_int, label: &[u16]) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -865,8 +840,7 @@ impl CefMenuModel {
   //
   pub fn get_type(&self,
       command_id: libc::c_int) -> types::cef_menu_item_type_t {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -881,8 +855,7 @@ impl CefMenuModel {
   // Returns the item type at the specified |index|.
   //
   pub fn get_type_at(&self, index: libc::c_int) -> types::cef_menu_item_type_t {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -897,8 +870,7 @@ impl CefMenuModel {
   // Returns the group id for the specified |command_id| or -1 if invalid.
   //
   pub fn get_group_id(&self, command_id: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -913,8 +885,7 @@ impl CefMenuModel {
   // Returns the group id at the specified |index| or -1 if invalid.
   //
   pub fn get_group_id_at(&self, index: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -931,8 +902,7 @@ impl CefMenuModel {
   //
   pub fn set_group_id(&self, command_id: libc::c_int,
       group_id: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -949,8 +919,7 @@ impl CefMenuModel {
   //
   pub fn set_group_id_at(&self, index: libc::c_int,
       group_id: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -967,8 +936,7 @@ impl CefMenuModel {
   //
   pub fn get_sub_menu(&self,
       command_id: libc::c_int) -> interfaces::CefMenuModel {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -984,8 +952,7 @@ impl CefMenuModel {
   //
   pub fn get_sub_menu_at(&self,
       index: libc::c_int) -> interfaces::CefMenuModel {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1000,8 +967,7 @@ impl CefMenuModel {
   // Returns true (1) if the specified |command_id| is visible.
   //
   pub fn is_visible(&self, command_id: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1016,8 +982,7 @@ impl CefMenuModel {
   // Returns true (1) if the specified |index| is visible.
   //
   pub fn is_visible_at(&self, index: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1034,8 +999,7 @@ impl CefMenuModel {
   //
   pub fn set_visible(&self, command_id: libc::c_int,
       visible: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1053,8 +1017,7 @@ impl CefMenuModel {
   //
   pub fn set_visible_at(&self, index: libc::c_int,
       visible: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1070,8 +1033,7 @@ impl CefMenuModel {
   // Returns true (1) if the specified |command_id| is enabled.
   //
   pub fn is_enabled(&self, command_id: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1086,8 +1048,7 @@ impl CefMenuModel {
   // Returns true (1) if the specified |index| is enabled.
   //
   pub fn is_enabled_at(&self, index: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1104,8 +1065,7 @@ impl CefMenuModel {
   //
   pub fn set_enabled(&self, command_id: libc::c_int,
       enabled: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1123,8 +1083,7 @@ impl CefMenuModel {
   //
   pub fn set_enabled_at(&self, index: libc::c_int,
       enabled: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1141,8 +1100,7 @@ impl CefMenuModel {
   // check and radio items.
   //
   pub fn is_checked(&self, command_id: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1158,8 +1116,7 @@ impl CefMenuModel {
   // and radio items.
   //
   pub fn is_checked_at(&self, index: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1176,8 +1133,7 @@ impl CefMenuModel {
   //
   pub fn set_checked(&self, command_id: libc::c_int,
       checked: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1195,8 +1151,7 @@ impl CefMenuModel {
   //
   pub fn set_checked_at(&self, index: libc::c_int,
       checked: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1213,8 +1168,7 @@ impl CefMenuModel {
   // assigned.
   //
   pub fn has_accelerator(&self, command_id: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1230,8 +1184,7 @@ impl CefMenuModel {
   // assigned.
   //
   pub fn has_accelerator_at(&self, index: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1249,8 +1202,7 @@ impl CefMenuModel {
   pub fn set_accelerator(&self, command_id: libc::c_int, key_code: libc::c_int,
       shift_pressed: libc::c_int, ctrl_pressed: libc::c_int,
       alt_pressed: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1272,8 +1224,7 @@ impl CefMenuModel {
   pub fn set_accelerator_at(&self, index: libc::c_int, key_code: libc::c_int,
       shift_pressed: libc::c_int, ctrl_pressed: libc::c_int,
       alt_pressed: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1293,8 +1244,7 @@ impl CefMenuModel {
   // true (1) on success.
   //
   pub fn remove_accelerator(&self, command_id: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1310,8 +1260,7 @@ impl CefMenuModel {
   // on success.
   //
   pub fn remove_accelerator_at(&self, index: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1330,8 +1279,7 @@ impl CefMenuModel {
       key_code: &mut libc::c_int, shift_pressed: &mut libc::c_int,
       ctrl_pressed: &mut libc::c_int,
       alt_pressed: &mut libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1354,8 +1302,7 @@ impl CefMenuModel {
       key_code: &mut libc::c_int, shift_pressed: &mut libc::c_int,
       ctrl_pressed: &mut libc::c_int,
       alt_pressed: &mut libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1387,8 +1334,7 @@ impl CefWrap<*mut cef_menu_model_t> for Option<CefMenuModel> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_menu_model_t) -> Option<CefMenuModel> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefMenuModel::from_c_object_addref(c_object))
diff --git a/ports/cef/interfaces/cef_navigation_entry.rs b/ports/cef/interfaces/cef_navigation_entry.rs
index 9d2a8b8a803..3deaa7fc6f1 100644
--- a/ports/cef/interfaces/cef_navigation_entry.rs
+++ b/ports/cef/interfaces/cef_navigation_entry.rs
@@ -145,8 +145,7 @@ pub struct CefNavigationEntry {
 impl Clone for CefNavigationEntry {
   fn clone(&self) -> CefNavigationEntry{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefNavigationEntry {
@@ -159,8 +158,7 @@ impl Clone for CefNavigationEntry {
 impl Drop for CefNavigationEntry {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -175,8 +173,7 @@ impl CefNavigationEntry {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_navigation_entry_t) -> CefNavigationEntry {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefNavigationEntry {
@@ -190,8 +187,7 @@ impl CefNavigationEntry {
 
   pub fn c_object_addrefed(&self) -> *mut cef_navigation_entry_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -199,10 +195,10 @@ impl CefNavigationEntry {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -210,8 +206,7 @@ impl CefNavigationEntry {
   // if this function returns false (0).
   //
   pub fn is_valid(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -227,8 +222,7 @@ impl CefNavigationEntry {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_url(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -243,8 +237,7 @@ impl CefNavigationEntry {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_display_url(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -259,8 +252,7 @@ impl CefNavigationEntry {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_original_url(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -275,8 +267,7 @@ impl CefNavigationEntry {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_title(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -291,8 +282,7 @@ impl CefNavigationEntry {
   // this page from the previous page.
   //
   pub fn get_transition_type(&self) -> types::cef_transition_type_t {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -306,8 +296,7 @@ impl CefNavigationEntry {
   // Returns true (1) if this navigation includes post data.
   //
   pub fn has_post_data(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -323,8 +312,7 @@ impl CefNavigationEntry {
   // 0 if the navigation has not yet completed.
   //
   pub fn get_completion_time(&self) -> types::cef_time_t {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -340,8 +328,7 @@ impl CefNavigationEntry {
   // navigation has not yet completed.
   //
   pub fn get_http_status_code(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -368,8 +355,7 @@ impl CefWrap<*mut cef_navigation_entry_t> for Option<CefNavigationEntry> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_navigation_entry_t) -> Option<CefNavigationEntry> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefNavigationEntry::from_c_object_addref(c_object))
diff --git a/ports/cef/interfaces/cef_print_handler.rs b/ports/cef/interfaces/cef_print_handler.rs
index adc0ebfcabc..020fddbd025 100644
--- a/ports/cef/interfaces/cef_print_handler.rs
+++ b/ports/cef/interfaces/cef_print_handler.rs
@@ -92,8 +92,7 @@ pub struct CefPrintDialogCallback {
 impl Clone for CefPrintDialogCallback {
   fn clone(&self) -> CefPrintDialogCallback{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefPrintDialogCallback {
@@ -106,8 +105,7 @@ impl Clone for CefPrintDialogCallback {
 impl Drop for CefPrintDialogCallback {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -122,8 +120,7 @@ impl CefPrintDialogCallback {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_print_dialog_callback_t) -> CefPrintDialogCallback {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefPrintDialogCallback {
@@ -137,8 +134,7 @@ impl CefPrintDialogCallback {
 
   pub fn c_object_addrefed(&self) -> *mut cef_print_dialog_callback_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -146,18 +142,17 @@ impl CefPrintDialogCallback {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
   // Continue printing with the specified |settings|.
   //
   pub fn cont(&self, settings: interfaces::CefPrintSettings) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -172,8 +167,7 @@ impl CefPrintDialogCallback {
   // Cancel the printing.
   //
   pub fn cancel(&self) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -200,8 +194,7 @@ impl CefWrap<*mut cef_print_dialog_callback_t> for Option<CefPrintDialogCallback
     }
   }
   unsafe fn to_rust(c_object: *mut cef_print_dialog_callback_t) -> Option<CefPrintDialogCallback> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefPrintDialogCallback::from_c_object_addref(c_object))
@@ -249,8 +242,7 @@ pub struct CefPrintJobCallback {
 impl Clone for CefPrintJobCallback {
   fn clone(&self) -> CefPrintJobCallback{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefPrintJobCallback {
@@ -263,8 +255,7 @@ impl Clone for CefPrintJobCallback {
 impl Drop for CefPrintJobCallback {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -279,8 +270,7 @@ impl CefPrintJobCallback {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_print_job_callback_t) -> CefPrintJobCallback {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefPrintJobCallback {
@@ -294,8 +284,7 @@ impl CefPrintJobCallback {
 
   pub fn c_object_addrefed(&self) -> *mut cef_print_job_callback_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -303,18 +292,17 @@ impl CefPrintJobCallback {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
   // Indicate completion of the print job.
   //
   pub fn cont(&self) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -341,8 +329,7 @@ impl CefWrap<*mut cef_print_job_callback_t> for Option<CefPrintJobCallback> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_print_job_callback_t) -> Option<CefPrintJobCallback> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefPrintJobCallback::from_c_object_addref(c_object))
@@ -428,8 +415,7 @@ pub struct CefPrintHandler {
 impl Clone for CefPrintHandler {
   fn clone(&self) -> CefPrintHandler{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefPrintHandler {
@@ -442,8 +428,7 @@ impl Clone for CefPrintHandler {
 impl Drop for CefPrintHandler {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -458,8 +443,7 @@ impl CefPrintHandler {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_print_handler_t) -> CefPrintHandler {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefPrintHandler {
@@ -473,8 +457,7 @@ impl CefPrintHandler {
 
   pub fn c_object_addrefed(&self) -> *mut cef_print_handler_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -482,10 +465,10 @@ impl CefPrintHandler {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -495,8 +478,7 @@ impl CefPrintHandler {
   //
   pub fn on_print_settings(&self, settings: interfaces::CefPrintSettings,
       get_defaults: libc::c_int) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -515,8 +497,7 @@ impl CefPrintHandler {
   //
   pub fn on_print_dialog(&self, has_selection: libc::c_int,
       callback: interfaces::CefPrintDialogCallback) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -535,8 +516,7 @@ impl CefPrintHandler {
   //
   pub fn on_print_job(&self, document_name: &[u16], pdf_file_path: &[u16],
       callback: interfaces::CefPrintJobCallback) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -553,8 +533,7 @@ impl CefPrintHandler {
   // Reset client state related to printing.
   //
   pub fn on_print_reset(&self) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -570,8 +549,7 @@ impl CefPrintHandler {
   //
   pub fn get_pdf_paper_size(&self,
       device_units_per_inch: libc::c_int) -> types::cef_size_t {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -599,8 +577,7 @@ impl CefWrap<*mut cef_print_handler_t> for Option<CefPrintHandler> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_print_handler_t) -> Option<CefPrintHandler> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefPrintHandler::from_c_object_addref(c_object))
diff --git a/ports/cef/interfaces/cef_print_settings.rs b/ports/cef/interfaces/cef_print_settings.rs
index 2c22df782ad..06bebf7dc34 100644
--- a/ports/cef/interfaces/cef_print_settings.rs
+++ b/ports/cef/interfaces/cef_print_settings.rs
@@ -228,8 +228,7 @@ pub struct CefPrintSettings {
 impl Clone for CefPrintSettings {
   fn clone(&self) -> CefPrintSettings{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefPrintSettings {
@@ -242,8 +241,7 @@ impl Clone for CefPrintSettings {
 impl Drop for CefPrintSettings {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -258,8 +256,7 @@ impl CefPrintSettings {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_print_settings_t) -> CefPrintSettings {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefPrintSettings {
@@ -273,8 +270,7 @@ impl CefPrintSettings {
 
   pub fn c_object_addrefed(&self) -> *mut cef_print_settings_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -282,10 +278,10 @@ impl CefPrintSettings {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -293,8 +289,7 @@ impl CefPrintSettings {
   // if this function returns false (0).
   //
   pub fn is_valid(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -309,8 +304,7 @@ impl CefPrintSettings {
   // expose read-only objects.
   //
   pub fn is_read_only(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -324,8 +318,7 @@ impl CefPrintSettings {
   // Returns a writable copy of this object.
   //
   pub fn copy(&self) -> interfaces::CefPrintSettings {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -339,8 +332,7 @@ impl CefPrintSettings {
   // Set the page orientation.
   //
   pub fn set_orientation(&self, landscape: libc::c_int) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -355,8 +347,7 @@ impl CefPrintSettings {
   // Returns true (1) if the orientation is landscape.
   //
   pub fn is_landscape(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -375,8 +366,7 @@ impl CefPrintSettings {
       physical_size_device_units: &types::cef_size_t,
       printable_area_device_units: &types::cef_rect_t,
       landscape_needs_flip: libc::c_int) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -393,8 +383,7 @@ impl CefPrintSettings {
   // Set the device name.
   //
   pub fn set_device_name(&self, name: &[u16]) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -410,8 +399,7 @@ impl CefPrintSettings {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_device_name(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -425,8 +413,7 @@ impl CefPrintSettings {
   // Set the DPI (dots per inch).
   //
   pub fn set_dpi(&self, dpi: libc::c_int) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -441,8 +428,7 @@ impl CefPrintSettings {
   // Get the DPI (dots per inch).
   //
   pub fn get_dpi(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -457,8 +443,7 @@ impl CefPrintSettings {
   //
   pub fn set_page_ranges(&self, ranges_count: libc::size_t,
       ranges: *const types::cef_page_range_t) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -474,8 +459,7 @@ impl CefPrintSettings {
   // Returns the number of page ranges that currently exist.
   //
   pub fn get_page_ranges_count(&self) -> libc::size_t {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -490,8 +474,7 @@ impl CefPrintSettings {
   //
   pub fn get_page_ranges(&self, ranges_count: *mut libc::size_t,
       ranges: *mut types::cef_page_range_t) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -507,8 +490,7 @@ impl CefPrintSettings {
   // Set whether only the selection will be printed.
   //
   pub fn set_selection_only(&self, selection_only: libc::c_int) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -523,8 +505,7 @@ impl CefPrintSettings {
   // Returns true (1) if only the selection will be printed.
   //
   pub fn is_selection_only(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -538,8 +519,7 @@ impl CefPrintSettings {
   // Set whether pages will be collated.
   //
   pub fn set_collate(&self, collate: libc::c_int) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -554,8 +534,7 @@ impl CefPrintSettings {
   // Returns true (1) if pages will be collated.
   //
   pub fn will_collate(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -569,8 +548,7 @@ impl CefPrintSettings {
   // Set the color model.
   //
   pub fn set_color_model(&self, model: types::cef_color_model_t) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -585,8 +563,7 @@ impl CefPrintSettings {
   // Get the color model.
   //
   pub fn get_color_model(&self) -> types::cef_color_model_t {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -600,8 +577,7 @@ impl CefPrintSettings {
   // Set the number of copies.
   //
   pub fn set_copies(&self, copies: libc::c_int) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -616,8 +592,7 @@ impl CefPrintSettings {
   // Get the number of copies.
   //
   pub fn get_copies(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -631,8 +606,7 @@ impl CefPrintSettings {
   // Set the duplex mode.
   //
   pub fn set_duplex_mode(&self, mode: types::cef_duplex_mode_t) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -647,8 +621,7 @@ impl CefPrintSettings {
   // Get the duplex mode.
   //
   pub fn get_duplex_mode(&self) -> types::cef_duplex_mode_t {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -686,8 +659,7 @@ impl CefWrap<*mut cef_print_settings_t> for Option<CefPrintSettings> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_print_settings_t) -> Option<CefPrintSettings> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefPrintSettings::from_c_object_addref(c_object))
diff --git a/ports/cef/interfaces/cef_process_message.rs b/ports/cef/interfaces/cef_process_message.rs
index e09b4b1ee15..16562683d29 100644
--- a/ports/cef/interfaces/cef_process_message.rs
+++ b/ports/cef/interfaces/cef_process_message.rs
@@ -113,8 +113,7 @@ pub struct CefProcessMessage {
 impl Clone for CefProcessMessage {
   fn clone(&self) -> CefProcessMessage{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefProcessMessage {
@@ -127,8 +126,7 @@ impl Clone for CefProcessMessage {
 impl Drop for CefProcessMessage {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -143,8 +141,7 @@ impl CefProcessMessage {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_process_message_t) -> CefProcessMessage {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefProcessMessage {
@@ -158,8 +155,7 @@ impl CefProcessMessage {
 
   pub fn c_object_addrefed(&self) -> *mut cef_process_message_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -167,10 +163,10 @@ impl CefProcessMessage {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -178,8 +174,7 @@ impl CefProcessMessage {
   // if this function returns false (0).
   //
   pub fn is_valid(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -194,8 +189,7 @@ impl CefProcessMessage {
   // expose read-only objects.
   //
   pub fn is_read_only(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -209,8 +203,7 @@ impl CefProcessMessage {
   // Returns a writable copy of this object.
   //
   pub fn copy(&self) -> interfaces::CefProcessMessage {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -225,8 +218,7 @@ impl CefProcessMessage {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_name(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -240,8 +232,7 @@ impl CefProcessMessage {
   // Returns the list of arguments.
   //
   pub fn get_argument_list(&self) -> interfaces::CefListValue {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -279,8 +270,7 @@ impl CefWrap<*mut cef_process_message_t> for Option<CefProcessMessage> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_process_message_t) -> Option<CefProcessMessage> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefProcessMessage::from_c_object_addref(c_object))
diff --git a/ports/cef/interfaces/cef_render_handler.rs b/ports/cef/interfaces/cef_render_handler.rs
index a813d7a8732..125bafede8f 100644
--- a/ports/cef/interfaces/cef_render_handler.rs
+++ b/ports/cef/interfaces/cef_render_handler.rs
@@ -213,8 +213,7 @@ pub struct CefRenderHandler {
 impl Clone for CefRenderHandler {
   fn clone(&self) -> CefRenderHandler{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefRenderHandler {
@@ -227,8 +226,7 @@ impl Clone for CefRenderHandler {
 impl Drop for CefRenderHandler {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -243,8 +241,7 @@ impl CefRenderHandler {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_render_handler_t) -> CefRenderHandler {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefRenderHandler {
@@ -258,8 +255,7 @@ impl CefRenderHandler {
 
   pub fn c_object_addrefed(&self) -> *mut cef_render_handler_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -267,10 +263,10 @@ impl CefRenderHandler {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -279,8 +275,7 @@ impl CefRenderHandler {
   //
   pub fn get_root_screen_rect(&self, browser: interfaces::CefBrowser,
       rect: &mut types::cef_rect_t) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -298,8 +293,7 @@ impl CefRenderHandler {
   //
   pub fn get_view_rect(&self, browser: interfaces::CefBrowser,
       rect: &mut types::cef_rect_t) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -318,8 +312,7 @@ impl CefRenderHandler {
   pub fn get_screen_point(&self, browser: interfaces::CefBrowser,
       viewX: libc::c_int, viewY: libc::c_int, screenX: &mut libc::c_int,
       screenY: &mut libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -345,8 +338,7 @@ impl CefRenderHandler {
   //
   pub fn get_screen_info(&self, browser: interfaces::CefBrowser,
       screen_info: &mut interfaces::CefScreenInfo) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -364,8 +356,7 @@ impl CefRenderHandler {
   //
   pub fn on_popup_show(&self, browser: interfaces::CefBrowser,
       show: libc::c_int) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -383,8 +374,7 @@ impl CefRenderHandler {
   //
   pub fn on_popup_size(&self, browser: interfaces::CefBrowser,
       rect: &types::cef_rect_t) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -410,8 +400,7 @@ impl CefRenderHandler {
       ty: types::cef_paint_element_type_t, dirtyRects_count: libc::size_t,
       dirtyRects: *const types::cef_rect_t, buffer: &(), width: libc::c_int,
       height: libc::c_int) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -435,8 +424,7 @@ impl CefRenderHandler {
   pub fn on_cursor_change(&self, browser: interfaces::CefBrowser,
       cursor: types::cef_cursor_handle_t, ty: types::cef_cursor_type_t,
       custom_cursor_info: &interfaces::CefCursorInfo) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -468,8 +456,7 @@ impl CefRenderHandler {
       drag_data: interfaces::CefDragData,
       allowed_ops: types::cef_drag_operations_mask_t, x: libc::c_int,
       y: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -491,8 +478,7 @@ impl CefRenderHandler {
   //
   pub fn update_drag_cursor(&self, browser: interfaces::CefBrowser,
       operation: types::cef_drag_operations_mask_t) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -509,8 +495,7 @@ impl CefRenderHandler {
   //
   pub fn on_scroll_offset_changed(&self, browser: interfaces::CefBrowser,
       x: libc::c_double, y: libc::c_double) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -531,8 +516,7 @@ impl CefRenderHandler {
   //
   pub fn get_backing_rect(&self, browser: interfaces::CefBrowser,
       rect: &mut types::cef_rect_t) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -549,8 +533,7 @@ impl CefRenderHandler {
   // flip). This is called only during accelerated compositing.
   //
   pub fn on_present(&self, browser: interfaces::CefBrowser) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -578,8 +561,7 @@ impl CefWrap<*mut cef_render_handler_t> for Option<CefRenderHandler> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_render_handler_t) -> Option<CefRenderHandler> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefRenderHandler::from_c_object_addref(c_object))
diff --git a/ports/cef/interfaces/cef_render_process_handler.rs b/ports/cef/interfaces/cef_render_process_handler.rs
index c334c9520e8..404d073a66b 100644
--- a/ports/cef/interfaces/cef_render_process_handler.rs
+++ b/ports/cef/interfaces/cef_render_process_handler.rs
@@ -197,8 +197,7 @@ pub struct CefRenderProcessHandler {
 impl Clone for CefRenderProcessHandler {
   fn clone(&self) -> CefRenderProcessHandler{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefRenderProcessHandler {
@@ -211,8 +210,7 @@ impl Clone for CefRenderProcessHandler {
 impl Drop for CefRenderProcessHandler {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -227,8 +225,7 @@ impl CefRenderProcessHandler {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_render_process_handler_t) -> CefRenderProcessHandler {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefRenderProcessHandler {
@@ -242,8 +239,7 @@ impl CefRenderProcessHandler {
 
   pub fn c_object_addrefed(&self) -> *mut cef_render_process_handler_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -251,10 +247,10 @@ impl CefRenderProcessHandler {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -265,8 +261,7 @@ impl CefRenderProcessHandler {
   //
   pub fn on_render_thread_created(&self,
       extra_info: interfaces::CefListValue) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -281,8 +276,7 @@ impl CefRenderProcessHandler {
   // Called after WebKit has been initialized.
   //
   pub fn on_web_kit_initialized(&self) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -298,8 +292,7 @@ impl CefRenderProcessHandler {
   // destroyed.
   //
   pub fn on_browser_created(&self, browser: interfaces::CefBrowser) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -314,8 +307,7 @@ impl CefRenderProcessHandler {
   // Called before a browser is destroyed.
   //
   pub fn on_browser_destroyed(&self, browser: interfaces::CefBrowser) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -330,8 +322,7 @@ impl CefRenderProcessHandler {
   // Return the handler for browser load status events.
   //
   pub fn get_load_handler(&self) -> interfaces::CefLoadHandler {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -350,8 +341,7 @@ impl CefRenderProcessHandler {
       frame: interfaces::CefFrame, request: interfaces::CefRequest,
       navigation_type: types::cef_navigation_type_t,
       is_redirect: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -376,8 +366,7 @@ impl CefRenderProcessHandler {
   //
   pub fn on_context_created(&self, browser: interfaces::CefBrowser,
       frame: interfaces::CefFrame, context: interfaces::CefV8Context) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -396,8 +385,7 @@ impl CefRenderProcessHandler {
   //
   pub fn on_context_released(&self, browser: interfaces::CefBrowser,
       frame: interfaces::CefFrame, context: interfaces::CefV8Context) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -419,8 +407,7 @@ impl CefRenderProcessHandler {
       frame: interfaces::CefFrame, context: interfaces::CefV8Context,
       exception: interfaces::CefV8Exception,
       stackTrace: interfaces::CefV8StackTrace) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -445,8 +432,7 @@ impl CefRenderProcessHandler {
   //
   pub fn on_focused_node_changed(&self, browser: interfaces::CefBrowser,
       frame: interfaces::CefFrame, node: interfaces::CefDOMNode) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -467,8 +453,7 @@ impl CefRenderProcessHandler {
   pub fn on_process_message_received(&self, browser: interfaces::CefBrowser,
       source_process: interfaces::CefProcessId,
       message: interfaces::CefProcessMessage) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -498,8 +483,7 @@ impl CefWrap<*mut cef_render_process_handler_t> for Option<CefRenderProcessHandl
     }
   }
   unsafe fn to_rust(c_object: *mut cef_render_process_handler_t) -> Option<CefRenderProcessHandler> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefRenderProcessHandler::from_c_object_addref(c_object))
diff --git a/ports/cef/interfaces/cef_request.rs b/ports/cef/interfaces/cef_request.rs
index 171d3c30314..d47a465fe86 100644
--- a/ports/cef/interfaces/cef_request.rs
+++ b/ports/cef/interfaces/cef_request.rs
@@ -197,8 +197,7 @@ pub struct CefRequest {
 impl Clone for CefRequest {
   fn clone(&self) -> CefRequest{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefRequest {
@@ -211,8 +210,7 @@ impl Clone for CefRequest {
 impl Drop for CefRequest {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -227,8 +225,7 @@ impl CefRequest {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_request_t) -> CefRequest {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefRequest {
@@ -242,8 +239,7 @@ impl CefRequest {
 
   pub fn c_object_addrefed(&self) -> *mut cef_request_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -251,18 +247,17 @@ impl CefRequest {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
   // Returns true (1) if this object is read-only.
   //
   pub fn is_read_only(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -277,8 +272,7 @@ impl CefRequest {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_url(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -292,8 +286,7 @@ impl CefRequest {
   // Set the fully qualified URL.
   //
   pub fn set_url(&self, url: &[u16]) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -310,8 +303,7 @@ impl CefRequest {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_method(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -325,8 +317,7 @@ impl CefRequest {
   // Set the request function type.
   //
   pub fn set_method(&self, method: &[u16]) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -341,8 +332,7 @@ impl CefRequest {
   // Get the post data.
   //
   pub fn get_post_data(&self) -> interfaces::CefPostData {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -356,8 +346,7 @@ impl CefRequest {
   // Set the post data.
   //
   pub fn set_post_data(&self, postData: interfaces::CefPostData) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -372,8 +361,7 @@ impl CefRequest {
   // Get the header values.
   //
   pub fn get_header_map(&self, headerMap: HashMap<String,Vec<String>>) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -388,8 +376,7 @@ impl CefRequest {
   // Set the header values.
   //
   pub fn set_header_map(&self, headerMap: HashMap<String,Vec<String>>) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -406,8 +393,7 @@ impl CefRequest {
   pub fn set(&self, url: &[u16], method: &[u16],
       postData: interfaces::CefPostData, headerMap: HashMap<String,
       Vec<String>>) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -426,8 +412,7 @@ impl CefRequest {
   // cef_urlrequest_flags_t for supported values.
   //
   pub fn get_flags(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -442,8 +427,7 @@ impl CefRequest {
   // cef_urlrequest_flags_t for supported values.
   //
   pub fn set_flags(&self, flags: libc::c_int) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -460,8 +444,7 @@ impl CefRequest {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_first_party_for_cookies(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -476,8 +459,7 @@ impl CefRequest {
   // cef_urlrequest_t.
   //
   pub fn set_first_party_for_cookies(&self, url: &[u16]) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -493,8 +475,7 @@ impl CefRequest {
   // process.
   //
   pub fn get_resource_type(&self) -> types::cef_resource_type_t {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -510,8 +491,7 @@ impl CefRequest {
   // frame navigation.
   //
   pub fn get_transition_type(&self) -> types::cef_transition_type_t {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -527,8 +507,7 @@ impl CefRequest {
   // browser process to track a single request across multiple callbacks.
   //
   pub fn get_identifier(&self) -> u64 {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -566,8 +545,7 @@ impl CefWrap<*mut cef_request_t> for Option<CefRequest> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_request_t) -> Option<CefRequest> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefRequest::from_c_object_addref(c_object))
@@ -649,8 +627,7 @@ pub struct CefPostData {
 impl Clone for CefPostData {
   fn clone(&self) -> CefPostData{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefPostData {
@@ -663,8 +640,7 @@ impl Clone for CefPostData {
 impl Drop for CefPostData {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -679,8 +655,7 @@ impl CefPostData {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_post_data_t) -> CefPostData {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefPostData {
@@ -694,8 +669,7 @@ impl CefPostData {
 
   pub fn c_object_addrefed(&self) -> *mut cef_post_data_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -703,18 +677,17 @@ impl CefPostData {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
   // Returns true (1) if this object is read-only.
   //
   pub fn is_read_only(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -728,8 +701,7 @@ impl CefPostData {
   // Returns the number of existing post data elements.
   //
   pub fn get_element_count(&self) -> libc::size_t {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -744,8 +716,7 @@ impl CefPostData {
   //
   pub fn get_elements(&self, elements_count: *mut libc::size_t,
       elements: *mut interfaces::CefPostDataElement) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -763,8 +734,7 @@ impl CefPostData {
   //
   pub fn remove_element(&self,
       element: interfaces::CefPostDataElement) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -780,8 +750,7 @@ impl CefPostData {
   //
   pub fn add_element(&self,
       element: interfaces::CefPostDataElement) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -796,8 +765,7 @@ impl CefPostData {
   // Remove all existing post data elements.
   //
   pub fn remove_elements(&self) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -835,8 +803,7 @@ impl CefWrap<*mut cef_post_data_t> for Option<CefPostData> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_post_data_t) -> Option<CefPostData> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefPostData::from_c_object_addref(c_object))
@@ -932,8 +899,7 @@ pub struct CefPostDataElement {
 impl Clone for CefPostDataElement {
   fn clone(&self) -> CefPostDataElement{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefPostDataElement {
@@ -946,8 +912,7 @@ impl Clone for CefPostDataElement {
 impl Drop for CefPostDataElement {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -962,8 +927,7 @@ impl CefPostDataElement {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_post_data_element_t) -> CefPostDataElement {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefPostDataElement {
@@ -977,8 +941,7 @@ impl CefPostDataElement {
 
   pub fn c_object_addrefed(&self) -> *mut cef_post_data_element_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -986,18 +949,17 @@ impl CefPostDataElement {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
   // Returns true (1) if this object is read-only.
   //
   pub fn is_read_only(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1011,8 +973,7 @@ impl CefPostDataElement {
   // Remove all contents from the post data element.
   //
   pub fn set_to_empty(&self) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1026,8 +987,7 @@ impl CefPostDataElement {
   // The post data element will represent a file.
   //
   pub fn set_to_file(&self, fileName: &[u16]) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1043,8 +1003,7 @@ impl CefPostDataElement {
   // copied.
   //
   pub fn set_to_bytes(&self, size: libc::size_t, bytes: &()) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1060,8 +1019,7 @@ impl CefPostDataElement {
   // Return the type of this post data element.
   //
   pub fn get_type(&self) -> types::cef_postdataelement_type_t {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1076,8 +1034,7 @@ impl CefPostDataElement {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_file(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1091,8 +1048,7 @@ impl CefPostDataElement {
   // Return the number of bytes.
   //
   pub fn get_bytes_count(&self) -> libc::size_t {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1107,8 +1063,7 @@ impl CefPostDataElement {
   // actually read.
   //
   pub fn get_bytes(&self, size: libc::size_t, bytes: &mut ()) -> libc::size_t {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1148,8 +1103,7 @@ impl CefWrap<*mut cef_post_data_element_t> for Option<CefPostDataElement> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_post_data_element_t) -> Option<CefPostDataElement> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefPostDataElement::from_c_object_addref(c_object))
diff --git a/ports/cef/interfaces/cef_request_context.rs b/ports/cef/interfaces/cef_request_context.rs
index 7f4f4fc975b..e5c639407a2 100644
--- a/ports/cef/interfaces/cef_request_context.rs
+++ b/ports/cef/interfaces/cef_request_context.rs
@@ -179,8 +179,7 @@ pub struct CefRequestContext {
 impl Clone for CefRequestContext {
   fn clone(&self) -> CefRequestContext{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefRequestContext {
@@ -193,8 +192,7 @@ impl Clone for CefRequestContext {
 impl Drop for CefRequestContext {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -209,8 +207,7 @@ impl CefRequestContext {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_request_context_t) -> CefRequestContext {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefRequestContext {
@@ -224,8 +221,7 @@ impl CefRequestContext {
 
   pub fn c_object_addrefed(&self) -> *mut cef_request_context_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -233,10 +229,10 @@ impl CefRequestContext {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -244,8 +240,7 @@ impl CefRequestContext {
   // object.
   //
   pub fn is_same(&self, other: interfaces::CefRequestContext) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -262,8 +257,7 @@ impl CefRequestContext {
   //
   pub fn is_sharing_with(&self,
       other: interfaces::CefRequestContext) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -280,8 +274,7 @@ impl CefRequestContext {
   // context argument.
   //
   pub fn is_global(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -295,8 +288,7 @@ impl CefRequestContext {
   // Returns the handler for this context if any.
   //
   pub fn get_handler(&self) -> interfaces::CefRequestContextHandler {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -312,8 +304,7 @@ impl CefRequestContext {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_cache_path(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -333,8 +324,7 @@ impl CefRequestContext {
   //
   pub fn get_default_cookie_manager(&self,
       callback: interfaces::CefCompletionCallback) -> interfaces::CefCookieManager {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -361,8 +351,7 @@ impl CefRequestContext {
   pub fn register_scheme_handler_factory(&self, scheme_name: &[u16],
       domain_name: &[u16],
       factory: interfaces::CefSchemeHandlerFactory) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -380,8 +369,7 @@ impl CefRequestContext {
   // This function may be called on any thread in the browser process.
   //
   pub fn clear_scheme_handler_factories(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -447,8 +435,7 @@ impl CefWrap<*mut cef_request_context_t> for Option<CefRequestContext> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_request_context_t) -> Option<CefRequestContext> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefRequestContext::from_c_object_addref(c_object))
diff --git a/ports/cef/interfaces/cef_request_context_handler.rs b/ports/cef/interfaces/cef_request_context_handler.rs
index 91e41a1b91e..a3ae82d1b80 100644
--- a/ports/cef/interfaces/cef_request_context_handler.rs
+++ b/ports/cef/interfaces/cef_request_context_handler.rs
@@ -92,8 +92,7 @@ pub struct CefRequestContextHandler {
 impl Clone for CefRequestContextHandler {
   fn clone(&self) -> CefRequestContextHandler{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefRequestContextHandler {
@@ -106,8 +105,7 @@ impl Clone for CefRequestContextHandler {
 impl Drop for CefRequestContextHandler {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -122,8 +120,7 @@ impl CefRequestContextHandler {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_request_context_handler_t) -> CefRequestContextHandler {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefRequestContextHandler {
@@ -137,8 +134,7 @@ impl CefRequestContextHandler {
 
   pub fn c_object_addrefed(&self) -> *mut cef_request_context_handler_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -146,10 +142,10 @@ impl CefRequestContextHandler {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -158,8 +154,7 @@ impl CefRequestContextHandler {
   // cef_request_tContext::get_default_cookie_manager() will be used.
   //
   pub fn get_cookie_manager(&self) -> interfaces::CefCookieManager {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -186,8 +181,7 @@ impl CefWrap<*mut cef_request_context_handler_t> for Option<CefRequestContextHan
     }
   }
   unsafe fn to_rust(c_object: *mut cef_request_context_handler_t) -> Option<CefRequestContextHandler> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefRequestContextHandler::from_c_object_addref(c_object))
diff --git a/ports/cef/interfaces/cef_request_handler.rs b/ports/cef/interfaces/cef_request_handler.rs
index 483d26adb9b..0ebeff40826 100644
--- a/ports/cef/interfaces/cef_request_handler.rs
+++ b/ports/cef/interfaces/cef_request_handler.rs
@@ -92,8 +92,7 @@ pub struct CefRequestCallback {
 impl Clone for CefRequestCallback {
   fn clone(&self) -> CefRequestCallback{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefRequestCallback {
@@ -106,8 +105,7 @@ impl Clone for CefRequestCallback {
 impl Drop for CefRequestCallback {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -122,8 +120,7 @@ impl CefRequestCallback {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_request_callback_t) -> CefRequestCallback {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefRequestCallback {
@@ -137,8 +134,7 @@ impl CefRequestCallback {
 
   pub fn c_object_addrefed(&self) -> *mut cef_request_callback_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -146,10 +142,10 @@ impl CefRequestCallback {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -157,8 +153,7 @@ impl CefRequestCallback {
   // continued. Otherwise, the request will be canceled.
   //
   pub fn cont(&self, allow: libc::c_int) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -173,8 +168,7 @@ impl CefRequestCallback {
   // Cancel the url request.
   //
   pub fn cancel(&self) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -201,8 +195,7 @@ impl CefWrap<*mut cef_request_callback_t> for Option<CefRequestCallback> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_request_callback_t) -> Option<CefRequestCallback> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefRequestCallback::from_c_object_addref(c_object))
@@ -426,8 +419,7 @@ pub struct CefRequestHandler {
 impl Clone for CefRequestHandler {
   fn clone(&self) -> CefRequestHandler{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefRequestHandler {
@@ -440,8 +432,7 @@ impl Clone for CefRequestHandler {
 impl Drop for CefRequestHandler {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -456,8 +447,7 @@ impl CefRequestHandler {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_request_handler_t) -> CefRequestHandler {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefRequestHandler {
@@ -471,8 +461,7 @@ impl CefRequestHandler {
 
   pub fn c_object_addrefed(&self) -> *mut cef_request_handler_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -480,10 +469,10 @@ impl CefRequestHandler {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -499,8 +488,7 @@ impl CefRequestHandler {
   pub fn on_before_browse(&self, browser: interfaces::CefBrowser,
       frame: interfaces::CefFrame, request: interfaces::CefRequest,
       is_redirect: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -534,8 +522,7 @@ impl CefRequestHandler {
       frame: interfaces::CefFrame, target_url: &[u16],
       target_disposition: types::cef_window_open_disposition_t,
       user_gesture: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -561,8 +548,7 @@ impl CefRequestHandler {
   pub fn on_before_resource_load(&self, browser: interfaces::CefBrowser,
       frame: interfaces::CefFrame, request: interfaces::CefRequest,
       callback: interfaces::CefRequestCallback) -> types::cef_return_value_t {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -585,8 +571,7 @@ impl CefRequestHandler {
   pub fn get_resource_handler(&self, browser: interfaces::CefBrowser,
       frame: interfaces::CefFrame,
       request: interfaces::CefRequest) -> interfaces::CefResourceHandler {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -608,8 +593,7 @@ impl CefRequestHandler {
   pub fn on_resource_redirect(&self, browser: interfaces::CefBrowser,
       frame: interfaces::CefFrame, request: interfaces::CefRequest,
       new_url: *mut types::cef_string_t) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -632,8 +616,7 @@ impl CefRequestHandler {
   pub fn on_resource_response(&self, browser: interfaces::CefBrowser,
       frame: interfaces::CefFrame, request: interfaces::CefRequest,
       response: interfaces::CefResponse) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -659,8 +642,7 @@ impl CefRequestHandler {
       frame: interfaces::CefFrame, isProxy: libc::c_int, host: &[u16],
       port: libc::c_int, realm: &[u16], scheme: &[u16],
       callback: interfaces::CefAuthCallback) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -690,8 +672,7 @@ impl CefRequestHandler {
   pub fn on_quota_request(&self, browser: interfaces::CefBrowser,
       origin_url: &[u16], new_size: i64,
       callback: interfaces::CefRequestCallback) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -714,8 +695,7 @@ impl CefRequestHandler {
   //
   pub fn on_protocol_execution(&self, browser: interfaces::CefBrowser,
       url: &[u16], allow_os_execution: &mut libc::c_int) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -741,8 +721,7 @@ impl CefRequestHandler {
       cert_error: types::cef_errorcode_t, request_url: &[u16],
       ssl_info: interfaces::CefSSLInfo,
       callback: interfaces::CefRequestCallback) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -764,8 +743,7 @@ impl CefRequestHandler {
   pub fn on_before_plugin_load(&self, browser: interfaces::CefBrowser,
       url: &[u16], policy_url: &[u16],
       info: interfaces::CefWebPluginInfo) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -785,8 +763,7 @@ impl CefRequestHandler {
   //
   pub fn on_plugin_crashed(&self, browser: interfaces::CefBrowser,
       plugin_path: &[u16]) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -804,8 +781,7 @@ impl CefRequestHandler {
   // process.
   //
   pub fn on_render_view_ready(&self, browser: interfaces::CefBrowser) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -822,8 +798,7 @@ impl CefRequestHandler {
   //
   pub fn on_render_process_terminated(&self, browser: interfaces::CefBrowser,
       status: types::cef_termination_status_t) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -852,8 +827,7 @@ impl CefWrap<*mut cef_request_handler_t> for Option<CefRequestHandler> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_request_handler_t) -> Option<CefRequestHandler> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefRequestHandler::from_c_object_addref(c_object))
diff --git a/ports/cef/interfaces/cef_resource_bundle_handler.rs b/ports/cef/interfaces/cef_resource_bundle_handler.rs
index d6501c0ea56..50f4e904405 100644
--- a/ports/cef/interfaces/cef_resource_bundle_handler.rs
+++ b/ports/cef/interfaces/cef_resource_bundle_handler.rs
@@ -105,8 +105,7 @@ pub struct CefResourceBundleHandler {
 impl Clone for CefResourceBundleHandler {
   fn clone(&self) -> CefResourceBundleHandler{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefResourceBundleHandler {
@@ -119,8 +118,7 @@ impl Clone for CefResourceBundleHandler {
 impl Drop for CefResourceBundleHandler {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -135,8 +133,7 @@ impl CefResourceBundleHandler {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_resource_bundle_handler_t) -> CefResourceBundleHandler {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefResourceBundleHandler {
@@ -150,8 +147,7 @@ impl CefResourceBundleHandler {
 
   pub fn c_object_addrefed(&self) -> *mut cef_resource_bundle_handler_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -159,10 +155,10 @@ impl CefResourceBundleHandler {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -173,8 +169,7 @@ impl CefResourceBundleHandler {
   //
   pub fn get_localized_string(&self, message_id: libc::c_int,
       string: *mut types::cef_string_t) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -197,8 +192,7 @@ impl CefResourceBundleHandler {
   pub fn get_data_resource(&self, resource_id: libc::c_int,
       data: &mut *mut libc::c_void,
       data_size: &mut libc::size_t) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -228,8 +222,7 @@ impl CefWrap<*mut cef_resource_bundle_handler_t> for Option<CefResourceBundleHan
     }
   }
   unsafe fn to_rust(c_object: *mut cef_resource_bundle_handler_t) -> Option<CefResourceBundleHandler> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefResourceBundleHandler::from_c_object_addref(c_object))
diff --git a/ports/cef/interfaces/cef_resource_handler.rs b/ports/cef/interfaces/cef_resource_handler.rs
index a6ecd42bc2e..27bbd9520f4 100644
--- a/ports/cef/interfaces/cef_resource_handler.rs
+++ b/ports/cef/interfaces/cef_resource_handler.rs
@@ -140,8 +140,7 @@ pub struct CefResourceHandler {
 impl Clone for CefResourceHandler {
   fn clone(&self) -> CefResourceHandler{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefResourceHandler {
@@ -154,8 +153,7 @@ impl Clone for CefResourceHandler {
 impl Drop for CefResourceHandler {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -170,8 +168,7 @@ impl CefResourceHandler {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_resource_handler_t) -> CefResourceHandler {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefResourceHandler {
@@ -185,8 +182,7 @@ impl CefResourceHandler {
 
   pub fn c_object_addrefed(&self) -> *mut cef_resource_handler_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -194,10 +190,10 @@ impl CefResourceHandler {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -209,8 +205,7 @@ impl CefResourceHandler {
   //
   pub fn process_request(&self, request: interfaces::CefRequest,
       callback: interfaces::CefCallback) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -235,8 +230,7 @@ impl CefResourceHandler {
   pub fn get_response_headers(&self, response: interfaces::CefResponse,
       response_length: &mut i64, redirectUrl: *mut types::cef_string_t) -> (
       ) {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -259,8 +253,7 @@ impl CefResourceHandler {
   pub fn read_response(&self, data_out: &mut (), bytes_to_read: libc::c_int,
       bytes_read: &mut libc::c_int,
       callback: interfaces::CefCallback) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -280,8 +273,7 @@ impl CefResourceHandler {
   // cookies will be sent with the request.
   //
   pub fn can_get_cookie(&self, cookie: &interfaces::CefCookie) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -297,8 +289,7 @@ impl CefResourceHandler {
   // set or false (0) otherwise.
   //
   pub fn can_set_cookie(&self, cookie: &interfaces::CefCookie) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -313,8 +304,7 @@ impl CefResourceHandler {
   // Request processing has been canceled.
   //
   pub fn cancel(&self) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -341,8 +331,7 @@ impl CefWrap<*mut cef_resource_handler_t> for Option<CefResourceHandler> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_resource_handler_t) -> Option<CefResourceHandler> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefResourceHandler::from_c_object_addref(c_object))
diff --git a/ports/cef/interfaces/cef_response.rs b/ports/cef/interfaces/cef_response.rs
index 54b45593991..bc61f60d0da 100644
--- a/ports/cef/interfaces/cef_response.rs
+++ b/ports/cef/interfaces/cef_response.rs
@@ -145,8 +145,7 @@ pub struct CefResponse {
 impl Clone for CefResponse {
   fn clone(&self) -> CefResponse{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefResponse {
@@ -159,8 +158,7 @@ impl Clone for CefResponse {
 impl Drop for CefResponse {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -175,8 +173,7 @@ impl CefResponse {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_response_t) -> CefResponse {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefResponse {
@@ -190,8 +187,7 @@ impl CefResponse {
 
   pub fn c_object_addrefed(&self) -> *mut cef_response_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -199,18 +195,17 @@ impl CefResponse {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
   // Returns true (1) if this object is read-only.
   //
   pub fn is_read_only(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -224,8 +219,7 @@ impl CefResponse {
   // Get the response status code.
   //
   pub fn get_status(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -239,8 +233,7 @@ impl CefResponse {
   // Set the response status code.
   //
   pub fn set_status(&self, status: libc::c_int) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -256,8 +249,7 @@ impl CefResponse {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_status_text(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -271,8 +263,7 @@ impl CefResponse {
   // Set the response status text.
   //
   pub fn set_status_text(&self, statusText: &[u16]) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -288,8 +279,7 @@ impl CefResponse {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_mime_type(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -303,8 +293,7 @@ impl CefResponse {
   // Set the response mime type.
   //
   pub fn set_mime_type(&self, mimeType: &[u16]) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -320,8 +309,7 @@ impl CefResponse {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_header(&self, name: &[u16]) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -336,8 +324,7 @@ impl CefResponse {
   // Get all response header fields.
   //
   pub fn get_header_map(&self, headerMap: HashMap<String,Vec<String>>) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -352,8 +339,7 @@ impl CefResponse {
   // Set all response header fields.
   //
   pub fn set_header_map(&self, headerMap: HashMap<String,Vec<String>>) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -392,8 +378,7 @@ impl CefWrap<*mut cef_response_t> for Option<CefResponse> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_response_t) -> Option<CefResponse> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefResponse::from_c_object_addref(c_object))
diff --git a/ports/cef/interfaces/cef_scheme.rs b/ports/cef/interfaces/cef_scheme.rs
index 2bf8a0030e3..db65269d343 100644
--- a/ports/cef/interfaces/cef_scheme.rs
+++ b/ports/cef/interfaces/cef_scheme.rs
@@ -130,8 +130,7 @@ pub struct CefSchemeRegistrar {
 impl Clone for CefSchemeRegistrar {
   fn clone(&self) -> CefSchemeRegistrar{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefSchemeRegistrar {
@@ -144,8 +143,7 @@ impl Clone for CefSchemeRegistrar {
 impl Drop for CefSchemeRegistrar {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -160,8 +158,7 @@ impl CefSchemeRegistrar {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_scheme_registrar_t) -> CefSchemeRegistrar {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefSchemeRegistrar {
@@ -175,8 +172,7 @@ impl CefSchemeRegistrar {
 
   pub fn c_object_addrefed(&self) -> *mut cef_scheme_registrar_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -184,10 +180,10 @@ impl CefSchemeRegistrar {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -239,8 +235,7 @@ impl CefSchemeRegistrar {
   pub fn add_custom_scheme(&self, scheme_name: &[u16], is_standard: libc::c_int,
       is_local: libc::c_int,
       is_display_isolated: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -271,8 +266,7 @@ impl CefWrap<*mut cef_scheme_registrar_t> for Option<CefSchemeRegistrar> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_scheme_registrar_t) -> Option<CefSchemeRegistrar> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefSchemeRegistrar::from_c_object_addref(c_object))
@@ -333,8 +327,7 @@ pub struct CefSchemeHandlerFactory {
 impl Clone for CefSchemeHandlerFactory {
   fn clone(&self) -> CefSchemeHandlerFactory{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefSchemeHandlerFactory {
@@ -347,8 +340,7 @@ impl Clone for CefSchemeHandlerFactory {
 impl Drop for CefSchemeHandlerFactory {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -363,8 +355,7 @@ impl CefSchemeHandlerFactory {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_scheme_handler_factory_t) -> CefSchemeHandlerFactory {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefSchemeHandlerFactory {
@@ -378,8 +369,7 @@ impl CefSchemeHandlerFactory {
 
   pub fn c_object_addrefed(&self) -> *mut cef_scheme_handler_factory_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -387,10 +377,10 @@ impl CefSchemeHandlerFactory {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -404,8 +394,7 @@ impl CefSchemeHandlerFactory {
   pub fn create(&self, browser: interfaces::CefBrowser,
       frame: interfaces::CefFrame, scheme_name: &[u16],
       request: interfaces::CefRequest) -> interfaces::CefResourceHandler {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -436,8 +425,7 @@ impl CefWrap<*mut cef_scheme_handler_factory_t> for Option<CefSchemeHandlerFacto
     }
   }
   unsafe fn to_rust(c_object: *mut cef_scheme_handler_factory_t) -> Option<CefSchemeHandlerFactory> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefSchemeHandlerFactory::from_c_object_addref(c_object))
diff --git a/ports/cef/interfaces/cef_ssl_info.rs b/ports/cef/interfaces/cef_ssl_info.rs
index 27108f472a7..9382e7e06e8 100644
--- a/ports/cef/interfaces/cef_ssl_info.rs
+++ b/ports/cef/interfaces/cef_ssl_info.rs
@@ -144,8 +144,7 @@ pub struct CefSSLCertPrincipal {
 impl Clone for CefSSLCertPrincipal {
   fn clone(&self) -> CefSSLCertPrincipal{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefSSLCertPrincipal {
@@ -158,8 +157,7 @@ impl Clone for CefSSLCertPrincipal {
 impl Drop for CefSSLCertPrincipal {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -174,8 +172,7 @@ impl CefSSLCertPrincipal {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_sslcert_principal_t) -> CefSSLCertPrincipal {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefSSLCertPrincipal {
@@ -189,8 +186,7 @@ impl CefSSLCertPrincipal {
 
   pub fn c_object_addrefed(&self) -> *mut cef_sslcert_principal_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -198,10 +194,10 @@ impl CefSSLCertPrincipal {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -210,8 +206,7 @@ impl CefSSLCertPrincipal {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_display_name(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -226,8 +221,7 @@ impl CefSSLCertPrincipal {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_common_name(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -242,8 +236,7 @@ impl CefSSLCertPrincipal {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_locality_name(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -258,8 +251,7 @@ impl CefSSLCertPrincipal {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_state_or_province_name(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -274,8 +266,7 @@ impl CefSSLCertPrincipal {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_country_name(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -289,8 +280,7 @@ impl CefSSLCertPrincipal {
   // Retrieve the list of street addresses.
   //
   pub fn get_street_addresses(&self, addresses: &Vec<String>) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -305,8 +295,7 @@ impl CefSSLCertPrincipal {
   // Retrieve the list of organization names.
   //
   pub fn get_organization_names(&self, names: &Vec<String>) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -321,8 +310,7 @@ impl CefSSLCertPrincipal {
   // Retrieve the list of organization unit names.
   //
   pub fn get_organization_unit_names(&self, names: &Vec<String>) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -337,8 +325,7 @@ impl CefSSLCertPrincipal {
   // Retrieve the list of domain components.
   //
   pub fn get_domain_components(&self, components: &Vec<String>) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -366,8 +353,7 @@ impl CefWrap<*mut cef_sslcert_principal_t> for Option<CefSSLCertPrincipal> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_sslcert_principal_t) -> Option<CefSSLCertPrincipal> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefSSLCertPrincipal::from_c_object_addref(c_object))
@@ -457,8 +443,7 @@ pub struct CefSSLInfo {
 impl Clone for CefSSLInfo {
   fn clone(&self) -> CefSSLInfo{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefSSLInfo {
@@ -471,8 +456,7 @@ impl Clone for CefSSLInfo {
 impl Drop for CefSSLInfo {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -487,8 +471,7 @@ impl CefSSLInfo {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_sslinfo_t) -> CefSSLInfo {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefSSLInfo {
@@ -502,8 +485,7 @@ impl CefSSLInfo {
 
   pub fn c_object_addrefed(&self) -> *mut cef_sslinfo_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -511,10 +493,10 @@ impl CefSSLInfo {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -523,8 +505,7 @@ impl CefSSLInfo {
   // match the host name of the web server.
   //
   pub fn get_subject(&self) -> interfaces::CefSSLCertPrincipal {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -538,8 +519,7 @@ impl CefSSLInfo {
   // Returns the issuer of the X.509 certificate.
   //
   pub fn get_issuer(&self) -> interfaces::CefSSLCertPrincipal {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -554,8 +534,7 @@ impl CefSSLInfo {
   // possibly includes a leading 00 byte.
   //
   pub fn get_serial_number(&self) -> interfaces::CefBinaryValue {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -570,8 +549,7 @@ impl CefSSLInfo {
   // CefTime.GetTimeT() will return 0 if no date was specified.
   //
   pub fn get_valid_start(&self) -> types::cef_time_t {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -586,8 +564,7 @@ impl CefSSLInfo {
   // CefTime.GetTimeT() will return 0 if no date was specified.
   //
   pub fn get_valid_expiry(&self) -> types::cef_time_t {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -601,8 +578,7 @@ impl CefSSLInfo {
   // Returns the DER encoded data for the X.509 certificate.
   //
   pub fn get_derencoded(&self) -> interfaces::CefBinaryValue {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -616,8 +592,7 @@ impl CefSSLInfo {
   // Returns the PEM encoded data for the X.509 certificate.
   //
   pub fn get_pemencoded(&self) -> interfaces::CefBinaryValue {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -644,8 +619,7 @@ impl CefWrap<*mut cef_sslinfo_t> for Option<CefSSLInfo> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_sslinfo_t) -> Option<CefSSLInfo> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefSSLInfo::from_c_object_addref(c_object))
diff --git a/ports/cef/interfaces/cef_stream.rs b/ports/cef/interfaces/cef_stream.rs
index 8489931a283..e4e1ede1557 100644
--- a/ports/cef/interfaces/cef_stream.rs
+++ b/ports/cef/interfaces/cef_stream.rs
@@ -113,8 +113,7 @@ pub struct CefReadHandler {
 impl Clone for CefReadHandler {
   fn clone(&self) -> CefReadHandler{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefReadHandler {
@@ -127,8 +126,7 @@ impl Clone for CefReadHandler {
 impl Drop for CefReadHandler {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -143,8 +141,7 @@ impl CefReadHandler {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_read_handler_t) -> CefReadHandler {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefReadHandler {
@@ -158,8 +155,7 @@ impl CefReadHandler {
 
   pub fn c_object_addrefed(&self) -> *mut cef_read_handler_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -167,10 +163,10 @@ impl CefReadHandler {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -178,8 +174,7 @@ impl CefReadHandler {
   //
   pub fn read(&self, ptr: &mut (), size: libc::size_t,
       n: libc::size_t) -> libc::size_t {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -197,8 +192,7 @@ impl CefReadHandler {
   // SEEK_END or SEEK_SET. Return zero on success and non-zero on failure.
   //
   pub fn seek(&self, offset: i64, whence: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -214,8 +208,7 @@ impl CefReadHandler {
   // Return the current offset position.
   //
   pub fn tell(&self) -> i64 {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -229,8 +222,7 @@ impl CefReadHandler {
   // Return non-zero if at end of file.
   //
   pub fn eof(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -246,8 +238,7 @@ impl CefReadHandler {
   // the handler from.
   //
   pub fn may_block(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -274,8 +265,7 @@ impl CefWrap<*mut cef_read_handler_t> for Option<CefReadHandler> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_read_handler_t) -> Option<CefReadHandler> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefReadHandler::from_c_object_addref(c_object))
@@ -351,8 +341,7 @@ pub struct CefStreamReader {
 impl Clone for CefStreamReader {
   fn clone(&self) -> CefStreamReader{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefStreamReader {
@@ -365,8 +354,7 @@ impl Clone for CefStreamReader {
 impl Drop for CefStreamReader {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -381,8 +369,7 @@ impl CefStreamReader {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_stream_reader_t) -> CefStreamReader {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefStreamReader {
@@ -396,8 +383,7 @@ impl CefStreamReader {
 
   pub fn c_object_addrefed(&self) -> *mut cef_stream_reader_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -405,10 +391,10 @@ impl CefStreamReader {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -416,8 +402,7 @@ impl CefStreamReader {
   //
   pub fn read(&self, ptr: &mut (), size: libc::size_t,
       n: libc::size_t) -> libc::size_t {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -435,8 +420,7 @@ impl CefStreamReader {
   // SEEK_END or SEEK_SET. Returns zero on success and non-zero on failure.
   //
   pub fn seek(&self, offset: i64, whence: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -452,8 +436,7 @@ impl CefStreamReader {
   // Return the current offset position.
   //
   pub fn tell(&self) -> i64 {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -467,8 +450,7 @@ impl CefStreamReader {
   // Return non-zero if at end of file.
   //
   pub fn eof(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -484,8 +466,7 @@ impl CefStreamReader {
   // the reader from.
   //
   pub fn may_block(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -548,8 +529,7 @@ impl CefWrap<*mut cef_stream_reader_t> for Option<CefStreamReader> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_stream_reader_t) -> Option<CefStreamReader> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefStreamReader::from_c_object_addref(c_object))
@@ -626,8 +606,7 @@ pub struct CefWriteHandler {
 impl Clone for CefWriteHandler {
   fn clone(&self) -> CefWriteHandler{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefWriteHandler {
@@ -640,8 +619,7 @@ impl Clone for CefWriteHandler {
 impl Drop for CefWriteHandler {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -656,8 +634,7 @@ impl CefWriteHandler {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_write_handler_t) -> CefWriteHandler {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefWriteHandler {
@@ -671,8 +648,7 @@ impl CefWriteHandler {
 
   pub fn c_object_addrefed(&self) -> *mut cef_write_handler_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -680,10 +656,10 @@ impl CefWriteHandler {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -691,8 +667,7 @@ impl CefWriteHandler {
   //
   pub fn write(&self, ptr: &(), size: libc::size_t,
       n: libc::size_t) -> libc::size_t {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -710,8 +685,7 @@ impl CefWriteHandler {
   // SEEK_END or SEEK_SET. Return zero on success and non-zero on failure.
   //
   pub fn seek(&self, offset: i64, whence: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -727,8 +701,7 @@ impl CefWriteHandler {
   // Return the current offset position.
   //
   pub fn tell(&self) -> i64 {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -742,8 +715,7 @@ impl CefWriteHandler {
   // Flush the stream.
   //
   pub fn flush(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -759,8 +731,7 @@ impl CefWriteHandler {
   // the handler from.
   //
   pub fn may_block(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -787,8 +758,7 @@ impl CefWrap<*mut cef_write_handler_t> for Option<CefWriteHandler> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_write_handler_t) -> Option<CefWriteHandler> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefWriteHandler::from_c_object_addref(c_object))
@@ -865,8 +835,7 @@ pub struct CefStreamWriter {
 impl Clone for CefStreamWriter {
   fn clone(&self) -> CefStreamWriter{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefStreamWriter {
@@ -879,8 +848,7 @@ impl Clone for CefStreamWriter {
 impl Drop for CefStreamWriter {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -895,8 +863,7 @@ impl CefStreamWriter {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_stream_writer_t) -> CefStreamWriter {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefStreamWriter {
@@ -910,8 +877,7 @@ impl CefStreamWriter {
 
   pub fn c_object_addrefed(&self) -> *mut cef_stream_writer_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -919,10 +885,10 @@ impl CefStreamWriter {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -930,8 +896,7 @@ impl CefStreamWriter {
   //
   pub fn write(&self, ptr: &(), size: libc::size_t,
       n: libc::size_t) -> libc::size_t {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -949,8 +914,7 @@ impl CefStreamWriter {
   // SEEK_END or SEEK_SET. Returns zero on success and non-zero on failure.
   //
   pub fn seek(&self, offset: i64, whence: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -966,8 +930,7 @@ impl CefStreamWriter {
   // Return the current offset position.
   //
   pub fn tell(&self) -> i64 {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -981,8 +944,7 @@ impl CefStreamWriter {
   // Flush the stream.
   //
   pub fn flush(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -998,8 +960,7 @@ impl CefStreamWriter {
   // the writer from.
   //
   pub fn may_block(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1049,8 +1010,7 @@ impl CefWrap<*mut cef_stream_writer_t> for Option<CefStreamWriter> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_stream_writer_t) -> Option<CefStreamWriter> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefStreamWriter::from_c_object_addref(c_object))
diff --git a/ports/cef/interfaces/cef_string_visitor.rs b/ports/cef/interfaces/cef_string_visitor.rs
index f895aa70643..7c94dd4bbe6 100644
--- a/ports/cef/interfaces/cef_string_visitor.rs
+++ b/ports/cef/interfaces/cef_string_visitor.rs
@@ -86,8 +86,7 @@ pub struct CefStringVisitor {
 impl Clone for CefStringVisitor {
   fn clone(&self) -> CefStringVisitor{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefStringVisitor {
@@ -100,8 +99,7 @@ impl Clone for CefStringVisitor {
 impl Drop for CefStringVisitor {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -116,8 +114,7 @@ impl CefStringVisitor {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_string_visitor_t) -> CefStringVisitor {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefStringVisitor {
@@ -131,8 +128,7 @@ impl CefStringVisitor {
 
   pub fn c_object_addrefed(&self) -> *mut cef_string_visitor_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -140,18 +136,17 @@ impl CefStringVisitor {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
   // Method that will be executed.
   //
   pub fn visit(&self, string: &[u16]) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -179,8 +174,7 @@ impl CefWrap<*mut cef_string_visitor_t> for Option<CefStringVisitor> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_string_visitor_t) -> Option<CefStringVisitor> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefStringVisitor::from_c_object_addref(c_object))
diff --git a/ports/cef/interfaces/cef_task.rs b/ports/cef/interfaces/cef_task.rs
index c41d48e93b8..9b60b025c73 100644
--- a/ports/cef/interfaces/cef_task.rs
+++ b/ports/cef/interfaces/cef_task.rs
@@ -95,8 +95,7 @@ pub struct CefTask {
 impl Clone for CefTask {
   fn clone(&self) -> CefTask{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefTask {
@@ -109,8 +108,7 @@ impl Clone for CefTask {
 impl Drop for CefTask {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -125,8 +123,7 @@ impl CefTask {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_task_t) -> CefTask {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefTask {
@@ -140,8 +137,7 @@ impl CefTask {
 
   pub fn c_object_addrefed(&self) -> *mut cef_task_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -149,18 +145,17 @@ impl CefTask {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
   // Method that will be executed on the target thread.
   //
   pub fn execute(&self) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -187,8 +182,7 @@ impl CefWrap<*mut cef_task_t> for Option<CefTask> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_task_t) -> Option<CefTask> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefTask::from_c_object_addref(c_object))
@@ -278,8 +272,7 @@ pub struct CefTaskRunner {
 impl Clone for CefTaskRunner {
   fn clone(&self) -> CefTaskRunner{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefTaskRunner {
@@ -292,8 +285,7 @@ impl Clone for CefTaskRunner {
 impl Drop for CefTaskRunner {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -308,8 +300,7 @@ impl CefTaskRunner {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_task_runner_t) -> CefTaskRunner {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefTaskRunner {
@@ -323,8 +314,7 @@ impl CefTaskRunner {
 
   pub fn c_object_addrefed(&self) -> *mut cef_task_runner_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -332,10 +322,10 @@ impl CefTaskRunner {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -343,8 +333,7 @@ impl CefTaskRunner {
   // |that| object.
   //
   pub fn is_same(&self, that: interfaces::CefTaskRunner) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -359,8 +348,7 @@ impl CefTaskRunner {
   // Returns true (1) if this task runner belongs to the current thread.
   //
   pub fn belongs_to_current_thread(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -375,8 +363,7 @@ impl CefTaskRunner {
   //
   pub fn belongs_to_thread(&self,
       threadId: types::cef_thread_id_t) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -392,8 +379,7 @@ impl CefTaskRunner {
   // Execution will occur asynchronously.
   //
   pub fn post_task(&self, task: interfaces::CefTask) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -412,8 +398,7 @@ impl CefTaskRunner {
   //
   pub fn post_delayed_task(&self, task: interfaces::CefTask,
       delay_ms: i64) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -467,8 +452,7 @@ impl CefWrap<*mut cef_task_runner_t> for Option<CefTaskRunner> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_task_runner_t) -> Option<CefTaskRunner> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefTaskRunner::from_c_object_addref(c_object))
diff --git a/ports/cef/interfaces/cef_trace.rs b/ports/cef/interfaces/cef_trace.rs
index 2a1793864bb..b2ebad90900 100644
--- a/ports/cef/interfaces/cef_trace.rs
+++ b/ports/cef/interfaces/cef_trace.rs
@@ -93,8 +93,7 @@ pub struct CefEndTracingCallback {
 impl Clone for CefEndTracingCallback {
   fn clone(&self) -> CefEndTracingCallback{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefEndTracingCallback {
@@ -107,8 +106,7 @@ impl Clone for CefEndTracingCallback {
 impl Drop for CefEndTracingCallback {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -123,8 +121,7 @@ impl CefEndTracingCallback {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_end_tracing_callback_t) -> CefEndTracingCallback {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefEndTracingCallback {
@@ -138,8 +135,7 @@ impl CefEndTracingCallback {
 
   pub fn c_object_addrefed(&self) -> *mut cef_end_tracing_callback_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -147,10 +143,10 @@ impl CefEndTracingCallback {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -159,8 +155,7 @@ impl CefEndTracingCallback {
   // deleting |tracing_file|.
   //
   pub fn on_end_tracing_complete(&self, tracing_file: &[u16]) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -188,8 +183,7 @@ impl CefWrap<*mut cef_end_tracing_callback_t> for Option<CefEndTracingCallback>
     }
   }
   unsafe fn to_rust(c_object: *mut cef_end_tracing_callback_t) -> Option<CefEndTracingCallback> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefEndTracingCallback::from_c_object_addref(c_object))
diff --git a/ports/cef/interfaces/cef_urlrequest.rs b/ports/cef/interfaces/cef_urlrequest.rs
index deec0bcdd6b..eb15bd66df0 100644
--- a/ports/cef/interfaces/cef_urlrequest.rs
+++ b/ports/cef/interfaces/cef_urlrequest.rs
@@ -127,8 +127,7 @@ pub struct CefURLRequest {
 impl Clone for CefURLRequest {
   fn clone(&self) -> CefURLRequest{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefURLRequest {
@@ -141,8 +140,7 @@ impl Clone for CefURLRequest {
 impl Drop for CefURLRequest {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -157,8 +155,7 @@ impl CefURLRequest {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_urlrequest_t) -> CefURLRequest {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefURLRequest {
@@ -172,8 +169,7 @@ impl CefURLRequest {
 
   pub fn c_object_addrefed(&self) -> *mut cef_urlrequest_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -181,10 +177,10 @@ impl CefURLRequest {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -192,8 +188,7 @@ impl CefURLRequest {
   // object is read-only and should not be modified.
   //
   pub fn get_request(&self) -> interfaces::CefRequest {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -207,8 +202,7 @@ impl CefURLRequest {
   // Returns the client.
   //
   pub fn get_client(&self) -> interfaces::CefURLRequestClient {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -222,8 +216,7 @@ impl CefURLRequest {
   // Returns the request status.
   //
   pub fn get_request_status(&self) -> types::cef_urlrequest_status_t {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -238,8 +231,7 @@ impl CefURLRequest {
   // otherwise.
   //
   pub fn get_request_error(&self) -> types::cef_errorcode_t {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -255,8 +247,7 @@ impl CefURLRequest {
   // The returned object is read-only and should not be modified.
   //
   pub fn get_response(&self) -> interfaces::CefResponse {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -270,8 +261,7 @@ impl CefURLRequest {
   // Cancel the request.
   //
   pub fn cancel(&self) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -325,8 +315,7 @@ impl CefWrap<*mut cef_urlrequest_t> for Option<CefURLRequest> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_urlrequest_t) -> Option<CefURLRequest> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefURLRequest::from_c_object_addref(c_object))
@@ -427,8 +416,7 @@ pub struct CefURLRequestClient {
 impl Clone for CefURLRequestClient {
   fn clone(&self) -> CefURLRequestClient{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefURLRequestClient {
@@ -441,8 +429,7 @@ impl Clone for CefURLRequestClient {
 impl Drop for CefURLRequestClient {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -457,8 +444,7 @@ impl CefURLRequestClient {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_urlrequest_client_t) -> CefURLRequestClient {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefURLRequestClient {
@@ -472,8 +458,7 @@ impl CefURLRequestClient {
 
   pub fn c_object_addrefed(&self) -> *mut cef_urlrequest_client_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -481,10 +466,10 @@ impl CefURLRequestClient {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -493,8 +478,7 @@ impl CefURLRequestClient {
   // successful or not.
   //
   pub fn on_request_complete(&self, request: interfaces::CefURLRequest) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -513,8 +497,7 @@ impl CefURLRequestClient {
   //
   pub fn on_upload_progress(&self, request: interfaces::CefURLRequest,
       current: i64, total: i64) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -534,8 +517,7 @@ impl CefURLRequestClient {
   //
   pub fn on_download_progress(&self, request: interfaces::CefURLRequest,
       current: i64, total: i64) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -555,8 +537,7 @@ impl CefURLRequestClient {
   //
   pub fn on_download_data(&self, request: interfaces::CefURLRequest, data: &(),
       data_length: libc::size_t) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -581,8 +562,7 @@ impl CefURLRequestClient {
   pub fn get_auth_credentials(&self, isProxy: libc::c_int, host: &[u16],
       port: libc::c_int, realm: &[u16], scheme: &[u16],
       callback: interfaces::CefAuthCallback) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -615,8 +595,7 @@ impl CefWrap<*mut cef_urlrequest_client_t> for Option<CefURLRequestClient> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_urlrequest_client_t) -> Option<CefURLRequestClient> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefURLRequestClient::from_c_object_addref(c_object))
diff --git a/ports/cef/interfaces/cef_v8.rs b/ports/cef/interfaces/cef_v8.rs
index eed48cc7a04..90fdead3d7f 100644
--- a/ports/cef/interfaces/cef_v8.rs
+++ b/ports/cef/interfaces/cef_v8.rs
@@ -157,8 +157,7 @@ pub struct CefV8Context {
 impl Clone for CefV8Context {
   fn clone(&self) -> CefV8Context{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefV8Context {
@@ -171,8 +170,7 @@ impl Clone for CefV8Context {
 impl Drop for CefV8Context {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -187,8 +185,7 @@ impl CefV8Context {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_v8context_t) -> CefV8Context {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefV8Context {
@@ -202,8 +199,7 @@ impl CefV8Context {
 
   pub fn c_object_addrefed(&self) -> *mut cef_v8context_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -211,10 +207,10 @@ impl CefV8Context {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -223,8 +219,7 @@ impl CefV8Context {
   // called on any render process thread.
   //
   pub fn get_task_runner(&self) -> interfaces::CefTaskRunner {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -240,8 +235,7 @@ impl CefV8Context {
   // returns false (0).
   //
   pub fn is_valid(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -256,8 +250,7 @@ impl CefV8Context {
   // reference for WebWorker contexts.
   //
   pub fn get_browser(&self) -> interfaces::CefBrowser {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -272,8 +265,7 @@ impl CefV8Context {
   // reference for WebWorker contexts.
   //
   pub fn get_frame(&self) -> interfaces::CefFrame {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -288,8 +280,7 @@ impl CefV8Context {
   // before calling this function.
   //
   pub fn get_global(&self) -> interfaces::CefV8Value {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -307,8 +298,7 @@ impl CefV8Context {
   // if the scope was entered successfully.
   //
   pub fn enter(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -323,8 +313,7 @@ impl CefV8Context {
   // true (1) if the scope was exited successfully.
   //
   pub fn exit(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -339,8 +328,7 @@ impl CefV8Context {
   // object.
   //
   pub fn is_same(&self, that: interfaces::CefV8Context) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -359,8 +347,7 @@ impl CefV8Context {
   //
   pub fn eval(&self, code: &[u16], retval: interfaces::CefV8Value,
       exception: interfaces::CefV8Exception) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -423,8 +410,7 @@ impl CefWrap<*mut cef_v8context_t> for Option<CefV8Context> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_v8context_t) -> Option<CefV8Context> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefV8Context::from_c_object_addref(c_object))
@@ -485,8 +471,7 @@ pub struct CefV8Handler {
 impl Clone for CefV8Handler {
   fn clone(&self) -> CefV8Handler{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefV8Handler {
@@ -499,8 +484,7 @@ impl Clone for CefV8Handler {
 impl Drop for CefV8Handler {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -515,8 +499,7 @@ impl CefV8Handler {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_v8handler_t) -> CefV8Handler {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefV8Handler {
@@ -530,8 +513,7 @@ impl CefV8Handler {
 
   pub fn c_object_addrefed(&self) -> *mut cef_v8handler_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -539,10 +521,10 @@ impl CefV8Handler {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -556,8 +538,7 @@ impl CefV8Handler {
       arguments_count: libc::size_t, arguments: *const interfaces::CefV8Value,
       retval: interfaces::CefV8Value,
       exception: *mut types::cef_string_t) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -590,8 +571,7 @@ impl CefWrap<*mut cef_v8handler_t> for Option<CefV8Handler> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_v8handler_t) -> Option<CefV8Handler> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefV8Handler::from_c_object_addref(c_object))
@@ -664,8 +644,7 @@ pub struct CefV8Accessor {
 impl Clone for CefV8Accessor {
   fn clone(&self) -> CefV8Accessor{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefV8Accessor {
@@ -678,8 +657,7 @@ impl Clone for CefV8Accessor {
 impl Drop for CefV8Accessor {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -694,8 +672,7 @@ impl CefV8Accessor {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_v8accessor_t) -> CefV8Accessor {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefV8Accessor {
@@ -709,8 +686,7 @@ impl CefV8Accessor {
 
   pub fn c_object_addrefed(&self) -> *mut cef_v8accessor_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -718,10 +694,10 @@ impl CefV8Accessor {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -734,8 +710,7 @@ impl CefV8Accessor {
   pub fn get(&self, name: &[u16], object: interfaces::CefV8Value,
       retval: interfaces::CefV8Value,
       exception: *mut types::cef_string_t) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -759,8 +734,7 @@ impl CefV8Accessor {
   pub fn set(&self, name: &[u16], object: interfaces::CefV8Value,
       value: interfaces::CefV8Value,
       exception: *mut types::cef_string_t) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -791,8 +765,7 @@ impl CefWrap<*mut cef_v8accessor_t> for Option<CefV8Accessor> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_v8accessor_t) -> Option<CefV8Accessor> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefV8Accessor::from_c_object_addref(c_object))
@@ -894,8 +867,7 @@ pub struct CefV8Exception {
 impl Clone for CefV8Exception {
   fn clone(&self) -> CefV8Exception{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefV8Exception {
@@ -908,8 +880,7 @@ impl Clone for CefV8Exception {
 impl Drop for CefV8Exception {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -924,8 +895,7 @@ impl CefV8Exception {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_v8exception_t) -> CefV8Exception {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefV8Exception {
@@ -939,8 +909,7 @@ impl CefV8Exception {
 
   pub fn c_object_addrefed(&self) -> *mut cef_v8exception_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -948,10 +917,10 @@ impl CefV8Exception {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -959,8 +928,7 @@ impl CefV8Exception {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_message(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -975,8 +943,7 @@ impl CefV8Exception {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_source_line(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -992,8 +959,7 @@ impl CefV8Exception {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_script_resource_name(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1008,8 +974,7 @@ impl CefV8Exception {
   // line number is unknown.
   //
   pub fn get_line_number(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1024,8 +989,7 @@ impl CefV8Exception {
   // occurred.
   //
   pub fn get_start_position(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1040,8 +1004,7 @@ impl CefV8Exception {
   // occurred.
   //
   pub fn get_end_position(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1056,8 +1019,7 @@ impl CefV8Exception {
   // occurred.
   //
   pub fn get_start_column(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1072,8 +1034,7 @@ impl CefV8Exception {
   // occurred.
   //
   pub fn get_end_column(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1100,8 +1061,7 @@ impl CefWrap<*mut cef_v8exception_t> for Option<CefV8Exception> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_v8exception_t) -> Option<CefV8Exception> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefV8Exception::from_c_object_addref(c_object))
@@ -1482,8 +1442,7 @@ pub struct CefV8Value {
 impl Clone for CefV8Value {
   fn clone(&self) -> CefV8Value{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefV8Value {
@@ -1496,8 +1455,7 @@ impl Clone for CefV8Value {
 impl Drop for CefV8Value {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -1512,8 +1470,7 @@ impl CefV8Value {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_v8value_t) -> CefV8Value {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefV8Value {
@@ -1527,8 +1484,7 @@ impl CefV8Value {
 
   pub fn c_object_addrefed(&self) -> *mut cef_v8value_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -1536,10 +1492,10 @@ impl CefV8Value {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -1548,8 +1504,7 @@ impl CefV8Value {
   // returns false (0).
   //
   pub fn is_valid(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1563,8 +1518,7 @@ impl CefV8Value {
   // True if the value type is undefined.
   //
   pub fn is_undefined(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1578,8 +1532,7 @@ impl CefV8Value {
   // True if the value type is null.
   //
   pub fn is_null(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1593,8 +1546,7 @@ impl CefV8Value {
   // True if the value type is bool.
   //
   pub fn is_bool(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1608,8 +1560,7 @@ impl CefV8Value {
   // True if the value type is int.
   //
   pub fn is_int(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1623,8 +1574,7 @@ impl CefV8Value {
   // True if the value type is unsigned int.
   //
   pub fn is_uint(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1638,8 +1588,7 @@ impl CefV8Value {
   // True if the value type is double.
   //
   pub fn is_double(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1653,8 +1602,7 @@ impl CefV8Value {
   // True if the value type is Date.
   //
   pub fn is_date(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1668,8 +1616,7 @@ impl CefV8Value {
   // True if the value type is string.
   //
   pub fn is_string(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1683,8 +1630,7 @@ impl CefV8Value {
   // True if the value type is object.
   //
   pub fn is_object(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1698,8 +1644,7 @@ impl CefV8Value {
   // True if the value type is array.
   //
   pub fn is_array(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1713,8 +1658,7 @@ impl CefV8Value {
   // True if the value type is function.
   //
   pub fn is_function(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1729,8 +1673,7 @@ impl CefV8Value {
   // object.
   //
   pub fn is_same(&self, that: interfaces::CefV8Value) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1746,8 +1689,7 @@ impl CefV8Value {
   // necessary.
   //
   pub fn get_bool_value(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1762,8 +1704,7 @@ impl CefV8Value {
   // necessary.
   //
   pub fn get_int_value(&self) -> i32 {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1778,8 +1719,7 @@ impl CefV8Value {
   // necessary.
   //
   pub fn get_uint_value(&self) -> u32 {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1794,8 +1734,7 @@ impl CefV8Value {
   // necessary.
   //
   pub fn get_double_value(&self) -> libc::c_double {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1810,8 +1749,7 @@ impl CefV8Value {
   // necessary.
   //
   pub fn get_date_value(&self) -> types::cef_time_t {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1827,8 +1765,7 @@ impl CefV8Value {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_string_value(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1847,8 +1784,7 @@ impl CefV8Value {
   // Returns true (1) if this is a user created object.
   //
   pub fn is_user_created(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1863,8 +1799,7 @@ impl CefV8Value {
   // attribute exists only in the scope of the current CEF value object.
   //
   pub fn has_exception(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1879,8 +1814,7 @@ impl CefV8Value {
   // exists only in the scope of the current CEF value object.
   //
   pub fn get_exception(&self) -> interfaces::CefV8Exception {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1894,8 +1828,7 @@ impl CefV8Value {
   // Clears the last exception and returns true (1) on success.
   //
   pub fn clear_exception(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1910,8 +1843,7 @@ impl CefV8Value {
   // attribute exists only in the scope of the current CEF value object.
   //
   pub fn will_rethrow_exceptions(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1929,8 +1861,7 @@ impl CefV8Value {
   // exists only in the scope of the current CEF value object.
   //
   pub fn set_rethrow_exceptions(&self, rethrow: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1945,8 +1876,7 @@ impl CefV8Value {
   // Returns true (1) if the object has a value with the specified identifier.
   //
   pub fn has_value_bykey(&self, key: &[u16]) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1961,8 +1891,7 @@ impl CefV8Value {
   // Returns true (1) if the object has a value with the specified identifier.
   //
   pub fn has_value_byindex(&self, index: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1980,8 +1909,7 @@ impl CefV8Value {
   // will return true (1) even though deletion failed.
   //
   pub fn delete_value_bykey(&self, key: &[u16]) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1999,8 +1927,7 @@ impl CefV8Value {
   // function will return true (1) even though deletion failed.
   //
   pub fn delete_value_byindex(&self, index: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2016,8 +1943,7 @@ impl CefV8Value {
   // this function is called incorrectly or an exception is thrown.
   //
   pub fn get_value_bykey(&self, key: &[u16]) -> interfaces::CefV8Value {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2034,8 +1960,7 @@ impl CefV8Value {
   //
   pub fn get_value_byindex(&self,
       index: libc::c_int) -> interfaces::CefV8Value {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2054,8 +1979,7 @@ impl CefV8Value {
   //
   pub fn set_value_bykey(&self, key: &[u16], value: interfaces::CefV8Value,
       attribute: types::cef_v8_propertyattribute_t) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2076,8 +2000,7 @@ impl CefV8Value {
   //
   pub fn set_value_byindex(&self, index: libc::c_int,
       value: interfaces::CefV8Value) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2099,8 +2022,7 @@ impl CefV8Value {
   pub fn set_value_byaccessor(&self, key: &[u16],
       settings: types::cef_v8_accesscontrol_t,
       attribute: types::cef_v8_propertyattribute_t) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2118,8 +2040,7 @@ impl CefV8Value {
   // based keys will also be returned as strings.
   //
   pub fn get_keys(&self, keys: &Vec<String>) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2136,8 +2057,7 @@ impl CefV8Value {
   // called on user created objects.
   //
   pub fn set_user_data(&self, user_data: interfaces::CefBase) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2152,8 +2072,7 @@ impl CefV8Value {
   // Returns the user data, if any, assigned to this object.
   //
   pub fn get_user_data(&self) -> interfaces::CefBase {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2168,8 +2087,7 @@ impl CefV8Value {
   // object.
   //
   pub fn get_externally_allocated_memory(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2192,8 +2110,7 @@ impl CefV8Value {
   //
   pub fn adjust_externally_allocated_memory(&self,
       change_in_bytes: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2211,8 +2128,7 @@ impl CefV8Value {
   // Returns the number of elements in the array.
   //
   pub fn get_array_length(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2230,8 +2146,7 @@ impl CefV8Value {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_function_name(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2245,8 +2160,7 @@ impl CefV8Value {
   // Returns the function handler or NULL if not a CEF-created function.
   //
   pub fn get_function_handler(&self) -> interfaces::CefV8Handler {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2270,8 +2184,7 @@ impl CefV8Value {
   pub fn execute_function(&self, object: interfaces::CefV8Value,
       arguments_count: libc::size_t,
       arguments: *const interfaces::CefV8Value) -> interfaces::CefV8Value {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2295,8 +2208,7 @@ impl CefV8Value {
   pub fn execute_function_with_context(&self, context: interfaces::CefV8Context,
       object: interfaces::CefV8Value, arguments_count: libc::size_t,
       arguments: *const interfaces::CefV8Value) -> interfaces::CefV8Value {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2466,8 +2378,7 @@ impl CefWrap<*mut cef_v8value_t> for Option<CefV8Value> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_v8value_t) -> Option<CefV8Value> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefV8Value::from_c_object_addref(c_object))
@@ -2538,8 +2449,7 @@ pub struct CefV8StackTrace {
 impl Clone for CefV8StackTrace {
   fn clone(&self) -> CefV8StackTrace{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefV8StackTrace {
@@ -2552,8 +2462,7 @@ impl Clone for CefV8StackTrace {
 impl Drop for CefV8StackTrace {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -2568,8 +2477,7 @@ impl CefV8StackTrace {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_v8stack_trace_t) -> CefV8StackTrace {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefV8StackTrace {
@@ -2583,8 +2491,7 @@ impl CefV8StackTrace {
 
   pub fn c_object_addrefed(&self) -> *mut cef_v8stack_trace_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -2592,10 +2499,10 @@ impl CefV8StackTrace {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -2604,8 +2511,7 @@ impl CefV8StackTrace {
   // returns false (0).
   //
   pub fn is_valid(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2619,8 +2525,7 @@ impl CefV8StackTrace {
   // Returns the number of stack frames.
   //
   pub fn get_frame_count(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2634,8 +2539,7 @@ impl CefV8StackTrace {
   // Returns the stack frame at the specified 0-based index.
   //
   pub fn get_frame(&self, index: libc::c_int) -> interfaces::CefV8StackFrame {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2675,8 +2579,7 @@ impl CefWrap<*mut cef_v8stack_trace_t> for Option<CefV8StackTrace> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_v8stack_trace_t) -> Option<CefV8StackTrace> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefV8StackTrace::from_c_object_addref(c_object))
@@ -2783,8 +2686,7 @@ pub struct CefV8StackFrame {
 impl Clone for CefV8StackFrame {
   fn clone(&self) -> CefV8StackFrame{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefV8StackFrame {
@@ -2797,8 +2699,7 @@ impl Clone for CefV8StackFrame {
 impl Drop for CefV8StackFrame {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -2813,8 +2714,7 @@ impl CefV8StackFrame {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_v8stack_frame_t) -> CefV8StackFrame {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefV8StackFrame {
@@ -2828,8 +2728,7 @@ impl CefV8StackFrame {
 
   pub fn c_object_addrefed(&self) -> *mut cef_v8stack_frame_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -2837,10 +2736,10 @@ impl CefV8StackFrame {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -2849,8 +2748,7 @@ impl CefV8StackFrame {
   // returns false (0).
   //
   pub fn is_valid(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2865,8 +2763,7 @@ impl CefV8StackFrame {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_script_name(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2883,8 +2780,7 @@ impl CefV8StackFrame {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_script_name_or_source_url(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2899,8 +2795,7 @@ impl CefV8StackFrame {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_function_name(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2914,8 +2809,7 @@ impl CefV8StackFrame {
   // Returns the 1-based line number for the function call or 0 if unknown.
   //
   pub fn get_line_number(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2930,8 +2824,7 @@ impl CefV8StackFrame {
   // unknown.
   //
   pub fn get_column(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2945,8 +2838,7 @@ impl CefV8StackFrame {
   // Returns true (1) if the function was compiled using eval().
   //
   pub fn is_eval(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2960,8 +2852,7 @@ impl CefV8StackFrame {
   // Returns true (1) if the function was called as a constructor via "new".
   //
   pub fn is_constructor(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2988,8 +2879,7 @@ impl CefWrap<*mut cef_v8stack_frame_t> for Option<CefV8StackFrame> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_v8stack_frame_t) -> Option<CefV8StackFrame> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefV8StackFrame::from_c_object_addref(c_object))
diff --git a/ports/cef/interfaces/cef_values.rs b/ports/cef/interfaces/cef_values.rs
index 8a9234b4e34..0283ae10b4e 100644
--- a/ports/cef/interfaces/cef_values.rs
+++ b/ports/cef/interfaces/cef_values.rs
@@ -247,8 +247,7 @@ pub struct CefValue {
 impl Clone for CefValue {
   fn clone(&self) -> CefValue{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefValue {
@@ -261,8 +260,7 @@ impl Clone for CefValue {
 impl Drop for CefValue {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -277,8 +275,7 @@ impl CefValue {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_value_t) -> CefValue {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefValue {
@@ -292,8 +289,7 @@ impl CefValue {
 
   pub fn c_object_addrefed(&self) -> *mut cef_value_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -301,10 +297,10 @@ impl CefValue {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -316,8 +312,7 @@ impl CefValue {
   // invalid.
   //
   pub fn is_valid(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -331,8 +326,7 @@ impl CefValue {
   // Returns true (1) if the underlying data is owned by another object.
   //
   pub fn is_owned(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -347,8 +341,7 @@ impl CefValue {
   // read-only objects.
   //
   pub fn is_read_only(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -364,8 +357,7 @@ impl CefValue {
   // object and vice-versa.
   //
   pub fn is_same(&self, that: interfaces::CefValue) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -381,8 +373,7 @@ impl CefValue {
   // underlying value but are not necessarily the same object.
   //
   pub fn is_equal(&self, that: interfaces::CefValue) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -397,8 +388,7 @@ impl CefValue {
   // Returns a copy of this object. The underlying data will also be copied.
   //
   pub fn copy(&self) -> interfaces::CefValue {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -412,8 +402,7 @@ impl CefValue {
   // Returns the underlying value type.
   //
   pub fn get_type(&self) -> interfaces::CefValueType {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -427,8 +416,7 @@ impl CefValue {
   // Returns the underlying value as type bool.
   //
   pub fn get_bool(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -442,8 +430,7 @@ impl CefValue {
   // Returns the underlying value as type int.
   //
   pub fn get_int(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -457,8 +444,7 @@ impl CefValue {
   // Returns the underlying value as type double.
   //
   pub fn get_double(&self) -> libc::c_double {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -473,8 +459,7 @@ impl CefValue {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_string(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -493,8 +478,7 @@ impl CefValue {
   // set_binary().
   //
   pub fn get_binary(&self) -> interfaces::CefBinaryValue {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -513,8 +497,7 @@ impl CefValue {
   // set_dictionary().
   //
   pub fn get_dictionary(&self) -> interfaces::CefDictionaryValue {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -533,8 +516,7 @@ impl CefValue {
   // set_list().
   //
   pub fn get_list(&self) -> interfaces::CefListValue {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -549,8 +531,7 @@ impl CefValue {
   // set successfully.
   //
   pub fn set_null(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -565,8 +546,7 @@ impl CefValue {
   // set successfully.
   //
   pub fn set_bool(&self, value: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -582,8 +562,7 @@ impl CefValue {
   // set successfully.
   //
   pub fn set_int(&self, value: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -599,8 +578,7 @@ impl CefValue {
   // set successfully.
   //
   pub fn set_double(&self, value: libc::c_double) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -616,8 +594,7 @@ impl CefValue {
   // set successfully.
   //
   pub fn set_string(&self, value: &[u16]) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -634,8 +611,7 @@ impl CefValue {
   // the underlying data remains unchanged.
   //
   pub fn set_binary(&self, value: interfaces::CefBinaryValue) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -653,8 +629,7 @@ impl CefValue {
   //
   pub fn set_dictionary(&self,
       value: interfaces::CefDictionaryValue) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -671,8 +646,7 @@ impl CefValue {
   // the underlying data remains unchanged.
   //
   pub fn set_list(&self, value: interfaces::CefListValue) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -711,8 +685,7 @@ impl CefWrap<*mut cef_value_t> for Option<CefValue> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_value_t) -> Option<CefValue> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefValue::from_c_object_addref(c_object))
@@ -804,8 +777,7 @@ pub struct CefBinaryValue {
 impl Clone for CefBinaryValue {
   fn clone(&self) -> CefBinaryValue{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefBinaryValue {
@@ -818,8 +790,7 @@ impl Clone for CefBinaryValue {
 impl Drop for CefBinaryValue {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -834,8 +805,7 @@ impl CefBinaryValue {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_binary_value_t) -> CefBinaryValue {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefBinaryValue {
@@ -849,8 +819,7 @@ impl CefBinaryValue {
 
   pub fn c_object_addrefed(&self) -> *mut cef_binary_value_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -858,10 +827,10 @@ impl CefBinaryValue {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -871,8 +840,7 @@ impl CefBinaryValue {
   // functions if this function returns false (0).
   //
   pub fn is_valid(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -886,8 +854,7 @@ impl CefBinaryValue {
   // Returns true (1) if this object is currently owned by another object.
   //
   pub fn is_owned(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -902,8 +869,7 @@ impl CefBinaryValue {
   // data.
   //
   pub fn is_same(&self, that: interfaces::CefBinaryValue) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -919,8 +885,7 @@ impl CefBinaryValue {
   // underlying value but are not necessarily the same object.
   //
   pub fn is_equal(&self, that: interfaces::CefBinaryValue) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -935,8 +900,7 @@ impl CefBinaryValue {
   // Returns a copy of this object. The data in this object will also be copied.
   //
   pub fn copy(&self) -> interfaces::CefBinaryValue {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -950,8 +914,7 @@ impl CefBinaryValue {
   // Returns the data size.
   //
   pub fn get_size(&self) -> libc::size_t {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -967,8 +930,7 @@ impl CefBinaryValue {
   //
   pub fn get_data(&self, buffer: &mut (), buffer_size: libc::size_t,
       data_offset: libc::size_t) -> libc::size_t {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1012,8 +974,7 @@ impl CefWrap<*mut cef_binary_value_t> for Option<CefBinaryValue> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_binary_value_t) -> Option<CefBinaryValue> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefBinaryValue::from_c_object_addref(c_object))
@@ -1278,8 +1239,7 @@ pub struct CefDictionaryValue {
 impl Clone for CefDictionaryValue {
   fn clone(&self) -> CefDictionaryValue{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefDictionaryValue {
@@ -1292,8 +1252,7 @@ impl Clone for CefDictionaryValue {
 impl Drop for CefDictionaryValue {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -1308,8 +1267,7 @@ impl CefDictionaryValue {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_dictionary_value_t) -> CefDictionaryValue {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefDictionaryValue {
@@ -1323,8 +1281,7 @@ impl CefDictionaryValue {
 
   pub fn c_object_addrefed(&self) -> *mut cef_dictionary_value_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -1332,10 +1289,10 @@ impl CefDictionaryValue {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -1345,8 +1302,7 @@ impl CefDictionaryValue {
   // functions if this function returns false (0).
   //
   pub fn is_valid(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1360,8 +1316,7 @@ impl CefDictionaryValue {
   // Returns true (1) if this object is currently owned by another object.
   //
   pub fn is_owned(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1376,8 +1331,7 @@ impl CefDictionaryValue {
   // expose read-only objects.
   //
   pub fn is_read_only(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1393,8 +1347,7 @@ impl CefDictionaryValue {
   // object and vice-versa.
   //
   pub fn is_same(&self, that: interfaces::CefDictionaryValue) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1410,8 +1363,7 @@ impl CefDictionaryValue {
   // underlying value but are not necessarily the same object.
   //
   pub fn is_equal(&self, that: interfaces::CefDictionaryValue) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1428,8 +1380,7 @@ impl CefDictionaryValue {
   //
   pub fn copy(&self,
       exclude_empty_children: libc::c_int) -> interfaces::CefDictionaryValue {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1444,8 +1395,7 @@ impl CefDictionaryValue {
   // Returns the number of values.
   //
   pub fn get_size(&self) -> libc::size_t {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1459,8 +1409,7 @@ impl CefDictionaryValue {
   // Removes all values. Returns true (1) on success.
   //
   pub fn clear(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1474,8 +1423,7 @@ impl CefDictionaryValue {
   // Returns true (1) if the current dictionary has a value for the given key.
   //
   pub fn has_key(&self, key: &[u16]) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1490,8 +1438,7 @@ impl CefDictionaryValue {
   // Reads all keys for this dictionary into the specified vector.
   //
   pub fn get_keys(&self, keys: &Vec<String>) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1507,8 +1454,7 @@ impl CefDictionaryValue {
   // removed successfully.
   //
   pub fn remove(&self, key: &[u16]) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1523,8 +1469,7 @@ impl CefDictionaryValue {
   // Returns the value type for the specified key.
   //
   pub fn get_type(&self, key: &[u16]) -> interfaces::CefValueType {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1543,8 +1488,7 @@ impl CefDictionaryValue {
   // this object.
   //
   pub fn get_value(&self, key: &[u16]) -> interfaces::CefValue {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1559,8 +1503,7 @@ impl CefDictionaryValue {
   // Returns the value at the specified key as type bool.
   //
   pub fn get_bool(&self, key: &[u16]) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1575,8 +1518,7 @@ impl CefDictionaryValue {
   // Returns the value at the specified key as type int.
   //
   pub fn get_int(&self, key: &[u16]) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1591,8 +1533,7 @@ impl CefDictionaryValue {
   // Returns the value at the specified key as type double.
   //
   pub fn get_double(&self, key: &[u16]) -> libc::c_double {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1608,8 +1549,7 @@ impl CefDictionaryValue {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_string(&self, key: &[u16]) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1625,8 +1565,7 @@ impl CefDictionaryValue {
   // will reference existing data.
   //
   pub fn get_binary(&self, key: &[u16]) -> interfaces::CefBinaryValue {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1643,8 +1582,7 @@ impl CefDictionaryValue {
   // modify this object.
   //
   pub fn get_dictionary(&self, key: &[u16]) -> interfaces::CefDictionaryValue {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1661,8 +1599,7 @@ impl CefDictionaryValue {
   // this object.
   //
   pub fn get_list(&self, key: &[u16]) -> interfaces::CefListValue {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1683,8 +1620,7 @@ impl CefDictionaryValue {
   //
   pub fn set_value(&self, key: &[u16],
       value: interfaces::CefValue) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1701,8 +1637,7 @@ impl CefDictionaryValue {
   // value was set successfully.
   //
   pub fn set_null(&self, key: &[u16]) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1718,8 +1653,7 @@ impl CefDictionaryValue {
   // value was set successfully.
   //
   pub fn set_bool(&self, key: &[u16], value: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1736,8 +1670,7 @@ impl CefDictionaryValue {
   // value was set successfully.
   //
   pub fn set_int(&self, key: &[u16], value: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1754,8 +1687,7 @@ impl CefDictionaryValue {
   // value was set successfully.
   //
   pub fn set_double(&self, key: &[u16], value: libc::c_double) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1772,8 +1704,7 @@ impl CefDictionaryValue {
   // value was set successfully.
   //
   pub fn set_string(&self, key: &[u16], value: &[u16]) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1794,8 +1725,7 @@ impl CefDictionaryValue {
   //
   pub fn set_binary(&self, key: &[u16],
       value: interfaces::CefBinaryValue) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1816,8 +1746,7 @@ impl CefDictionaryValue {
   //
   pub fn set_dictionary(&self, key: &[u16],
       value: interfaces::CefDictionaryValue) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1838,8 +1767,7 @@ impl CefDictionaryValue {
   //
   pub fn set_list(&self, key: &[u16],
       value: interfaces::CefListValue) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -1879,8 +1807,7 @@ impl CefWrap<*mut cef_dictionary_value_t> for Option<CefDictionaryValue> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_dictionary_value_t) -> Option<CefDictionaryValue> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefDictionaryValue::from_c_object_addref(c_object))
@@ -2133,8 +2060,7 @@ pub struct CefListValue {
 impl Clone for CefListValue {
   fn clone(&self) -> CefListValue{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefListValue {
@@ -2147,8 +2073,7 @@ impl Clone for CefListValue {
 impl Drop for CefListValue {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -2163,8 +2088,7 @@ impl CefListValue {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_list_value_t) -> CefListValue {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefListValue {
@@ -2178,8 +2102,7 @@ impl CefListValue {
 
   pub fn c_object_addrefed(&self) -> *mut cef_list_value_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -2187,10 +2110,10 @@ impl CefListValue {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -2200,8 +2123,7 @@ impl CefListValue {
   // functions if this function returns false (0).
   //
   pub fn is_valid(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2215,8 +2137,7 @@ impl CefListValue {
   // Returns true (1) if this object is currently owned by another object.
   //
   pub fn is_owned(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2231,8 +2152,7 @@ impl CefListValue {
   // expose read-only objects.
   //
   pub fn is_read_only(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2248,8 +2168,7 @@ impl CefListValue {
   // object and vice-versa.
   //
   pub fn is_same(&self, that: interfaces::CefListValue) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2265,8 +2184,7 @@ impl CefListValue {
   // underlying value but are not necessarily the same object.
   //
   pub fn is_equal(&self, that: interfaces::CefListValue) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2281,8 +2199,7 @@ impl CefListValue {
   // Returns a writable copy of this object.
   //
   pub fn copy(&self) -> interfaces::CefListValue {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2297,8 +2214,7 @@ impl CefListValue {
   // value slots will default to type null. Returns true (1) on success.
   //
   pub fn set_size(&self, size: libc::size_t) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2313,8 +2229,7 @@ impl CefListValue {
   // Returns the number of values.
   //
   pub fn get_size(&self) -> libc::size_t {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2328,8 +2243,7 @@ impl CefListValue {
   // Removes all values. Returns true (1) on success.
   //
   pub fn clear(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2343,8 +2257,7 @@ impl CefListValue {
   // Removes the value at the specified index.
   //
   pub fn remove(&self, index: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2359,8 +2272,7 @@ impl CefListValue {
   // Returns the value type at the specified index.
   //
   pub fn get_type(&self, index: libc::c_int) -> interfaces::CefValueType {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2379,8 +2291,7 @@ impl CefListValue {
   // will modify this object.
   //
   pub fn get_value(&self, index: libc::c_int) -> interfaces::CefValue {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2395,8 +2306,7 @@ impl CefListValue {
   // Returns the value at the specified index as type bool.
   //
   pub fn get_bool(&self, index: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2411,8 +2321,7 @@ impl CefListValue {
   // Returns the value at the specified index as type int.
   //
   pub fn get_int(&self, index: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2427,8 +2336,7 @@ impl CefListValue {
   // Returns the value at the specified index as type double.
   //
   pub fn get_double(&self, index: libc::c_int) -> libc::c_double {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2444,8 +2352,7 @@ impl CefListValue {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_string(&self, index: libc::c_int) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2461,8 +2368,7 @@ impl CefListValue {
   // will reference existing data.
   //
   pub fn get_binary(&self, index: libc::c_int) -> interfaces::CefBinaryValue {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2480,8 +2386,7 @@ impl CefListValue {
   //
   pub fn get_dictionary(&self,
       index: libc::c_int) -> interfaces::CefDictionaryValue {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2498,8 +2403,7 @@ impl CefListValue {
   // this object.
   //
   pub fn get_list(&self, index: libc::c_int) -> interfaces::CefListValue {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2520,8 +2424,7 @@ impl CefListValue {
   //
   pub fn set_value(&self, index: libc::c_int,
       value: interfaces::CefValue) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2538,8 +2441,7 @@ impl CefListValue {
   // value was set successfully.
   //
   pub fn set_null(&self, index: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2556,8 +2458,7 @@ impl CefListValue {
   //
   pub fn set_bool(&self, index: libc::c_int,
       value: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2574,8 +2475,7 @@ impl CefListValue {
   // value was set successfully.
   //
   pub fn set_int(&self, index: libc::c_int, value: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2593,8 +2493,7 @@ impl CefListValue {
   //
   pub fn set_double(&self, index: libc::c_int,
       value: libc::c_double) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2611,8 +2510,7 @@ impl CefListValue {
   // the value was set successfully.
   //
   pub fn set_string(&self, index: libc::c_int, value: &[u16]) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2633,8 +2531,7 @@ impl CefListValue {
   //
   pub fn set_binary(&self, index: libc::c_int,
       value: interfaces::CefBinaryValue) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2655,8 +2552,7 @@ impl CefListValue {
   //
   pub fn set_dictionary(&self, index: libc::c_int,
       value: interfaces::CefDictionaryValue) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2677,8 +2573,7 @@ impl CefListValue {
   //
   pub fn set_list(&self, index: libc::c_int,
       value: interfaces::CefListValue) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -2718,8 +2613,7 @@ impl CefWrap<*mut cef_list_value_t> for Option<CefListValue> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_list_value_t) -> Option<CefListValue> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefListValue::from_c_object_addref(c_object))
diff --git a/ports/cef/interfaces/cef_web_plugin.rs b/ports/cef/interfaces/cef_web_plugin.rs
index 94019e77ef5..705cc24ad04 100644
--- a/ports/cef/interfaces/cef_web_plugin.rs
+++ b/ports/cef/interfaces/cef_web_plugin.rs
@@ -108,8 +108,7 @@ pub struct CefWebPluginInfo {
 impl Clone for CefWebPluginInfo {
   fn clone(&self) -> CefWebPluginInfo{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefWebPluginInfo {
@@ -122,8 +121,7 @@ impl Clone for CefWebPluginInfo {
 impl Drop for CefWebPluginInfo {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -138,8 +136,7 @@ impl CefWebPluginInfo {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_web_plugin_info_t) -> CefWebPluginInfo {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefWebPluginInfo {
@@ -153,8 +150,7 @@ impl CefWebPluginInfo {
 
   pub fn c_object_addrefed(&self) -> *mut cef_web_plugin_info_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -162,10 +158,10 @@ impl CefWebPluginInfo {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -173,8 +169,7 @@ impl CefWebPluginInfo {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_name(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -189,8 +184,7 @@ impl CefWebPluginInfo {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_path(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -205,8 +199,7 @@ impl CefWebPluginInfo {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_version(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -221,8 +214,7 @@ impl CefWebPluginInfo {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_description(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -249,8 +241,7 @@ impl CefWrap<*mut cef_web_plugin_info_t> for Option<CefWebPluginInfo> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_web_plugin_info_t) -> Option<CefWebPluginInfo> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefWebPluginInfo::from_c_object_addref(c_object))
@@ -305,8 +296,7 @@ pub struct CefWebPluginInfoVisitor {
 impl Clone for CefWebPluginInfoVisitor {
   fn clone(&self) -> CefWebPluginInfoVisitor{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefWebPluginInfoVisitor {
@@ -319,8 +309,7 @@ impl Clone for CefWebPluginInfoVisitor {
 impl Drop for CefWebPluginInfoVisitor {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -335,8 +324,7 @@ impl CefWebPluginInfoVisitor {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_web_plugin_info_visitor_t) -> CefWebPluginInfoVisitor {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefWebPluginInfoVisitor {
@@ -350,8 +338,7 @@ impl CefWebPluginInfoVisitor {
 
   pub fn c_object_addrefed(&self) -> *mut cef_web_plugin_info_visitor_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -359,10 +346,10 @@ impl CefWebPluginInfoVisitor {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -373,8 +360,7 @@ impl CefWebPluginInfoVisitor {
   //
   pub fn visit(&self, info: interfaces::CefWebPluginInfo, count: libc::c_int,
       total: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -404,8 +390,7 @@ impl CefWrap<*mut cef_web_plugin_info_visitor_t> for Option<CefWebPluginInfoVisi
     }
   }
   unsafe fn to_rust(c_object: *mut cef_web_plugin_info_visitor_t) -> Option<CefWebPluginInfoVisitor> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefWebPluginInfoVisitor::from_c_object_addref(c_object))
@@ -459,8 +444,7 @@ pub struct CefWebPluginUnstableCallback {
 impl Clone for CefWebPluginUnstableCallback {
   fn clone(&self) -> CefWebPluginUnstableCallback{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefWebPluginUnstableCallback {
@@ -473,8 +457,7 @@ impl Clone for CefWebPluginUnstableCallback {
 impl Drop for CefWebPluginUnstableCallback {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -489,8 +472,7 @@ impl CefWebPluginUnstableCallback {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_web_plugin_unstable_callback_t) -> CefWebPluginUnstableCallback {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefWebPluginUnstableCallback {
@@ -504,8 +486,7 @@ impl CefWebPluginUnstableCallback {
 
   pub fn c_object_addrefed(&self) -> *mut cef_web_plugin_unstable_callback_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -513,10 +494,10 @@ impl CefWebPluginUnstableCallback {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -525,8 +506,7 @@ impl CefWebPluginUnstableCallback {
   // 120 seconds.
   //
   pub fn is_unstable(&self, path: &[u16], unstable: libc::c_int) -> () {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -555,8 +535,7 @@ impl CefWrap<*mut cef_web_plugin_unstable_callback_t> for Option<CefWebPluginUns
     }
   }
   unsafe fn to_rust(c_object: *mut cef_web_plugin_unstable_callback_t) -> Option<CefWebPluginUnstableCallback> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefWebPluginUnstableCallback::from_c_object_addref(c_object))
diff --git a/ports/cef/interfaces/cef_xml_reader.rs b/ports/cef/interfaces/cef_xml_reader.rs
index 485ef4c2ee7..0de8b956a7d 100644
--- a/ports/cef/interfaces/cef_xml_reader.rs
+++ b/ports/cef/interfaces/cef_xml_reader.rs
@@ -301,8 +301,7 @@ pub struct CefXmlReader {
 impl Clone for CefXmlReader {
   fn clone(&self) -> CefXmlReader{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefXmlReader {
@@ -315,8 +314,7 @@ impl Clone for CefXmlReader {
 impl Drop for CefXmlReader {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -331,8 +329,7 @@ impl CefXmlReader {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_xml_reader_t) -> CefXmlReader {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefXmlReader {
@@ -346,8 +343,7 @@ impl CefXmlReader {
 
   pub fn c_object_addrefed(&self) -> *mut cef_xml_reader_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -355,10 +351,10 @@ impl CefXmlReader {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -367,8 +363,7 @@ impl CefXmlReader {
   // if the cursor position was set successfully.
   //
   pub fn move_to_next_node(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -383,8 +378,7 @@ impl CefXmlReader {
   // occurs on the correct thread.
   //
   pub fn close(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -398,8 +392,7 @@ impl CefXmlReader {
   // Returns true (1) if an error has been reported by the XML parser.
   //
   pub fn has_error(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -414,8 +407,7 @@ impl CefXmlReader {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_error(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -433,8 +425,7 @@ impl CefXmlReader {
   // Returns the node type.
   //
   pub fn get_type(&self) -> types::cef_xml_node_type_t {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -448,8 +439,7 @@ impl CefXmlReader {
   // Returns the node depth. Depth starts at 0 for the root node.
   //
   pub fn get_depth(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -465,8 +455,7 @@ impl CefXmlReader {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_local_name(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -482,8 +471,7 @@ impl CefXmlReader {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_prefix(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -499,8 +487,7 @@ impl CefXmlReader {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_qualified_name(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -516,8 +503,7 @@ impl CefXmlReader {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_namespace_uri(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -533,8 +519,7 @@ impl CefXmlReader {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_base_uri(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -550,8 +535,7 @@ impl CefXmlReader {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_xml_lang(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -566,8 +550,7 @@ impl CefXmlReader {
   // NULL but <a></a> is not.
   //
   pub fn is_empty_element(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -581,8 +564,7 @@ impl CefXmlReader {
   // Returns true (1) if the node has a text value.
   //
   pub fn has_value(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -597,8 +579,7 @@ impl CefXmlReader {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_value(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -612,8 +593,7 @@ impl CefXmlReader {
   // Returns true (1) if the node has attributes.
   //
   pub fn has_attributes(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -627,8 +607,7 @@ impl CefXmlReader {
   // Returns the number of attributes.
   //
   pub fn get_attribute_count(&self) -> libc::size_t {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -643,8 +622,7 @@ impl CefXmlReader {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_attribute_byindex(&self, index: libc::c_int) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -660,8 +638,7 @@ impl CefXmlReader {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_attribute_byqname(&self, qualifiedName: &[u16]) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -679,8 +656,7 @@ impl CefXmlReader {
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_attribute_bylname(&self, localName: &[u16],
       namespaceURI: &[u16]) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -697,8 +673,7 @@ impl CefXmlReader {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_inner_xml(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -713,8 +688,7 @@ impl CefXmlReader {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_outer_xml(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -728,8 +702,7 @@ impl CefXmlReader {
   // Returns the line number for the current node.
   //
   pub fn get_line_number(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -750,8 +723,7 @@ impl CefXmlReader {
   // true (1) if the cursor position was set successfully.
   //
   pub fn move_to_attribute_byindex(&self, index: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -768,8 +740,7 @@ impl CefXmlReader {
   //
   pub fn move_to_attribute_byqname(&self,
       qualifiedName: &[u16]) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -787,8 +758,7 @@ impl CefXmlReader {
   //
   pub fn move_to_attribute_bylname(&self, localName: &[u16],
       namespaceURI: &[u16]) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -805,8 +775,7 @@ impl CefXmlReader {
   // true (1) if the cursor position was set successfully.
   //
   pub fn move_to_first_attribute(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -821,8 +790,7 @@ impl CefXmlReader {
   // (1) if the cursor position was set successfully.
   //
   pub fn move_to_next_attribute(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -837,8 +805,7 @@ impl CefXmlReader {
   // cursor position was set successfully.
   //
   pub fn move_to_carrying_element(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -881,8 +848,7 @@ impl CefWrap<*mut cef_xml_reader_t> for Option<CefXmlReader> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_xml_reader_t) -> Option<CefXmlReader> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefXmlReader::from_c_object_addref(c_object))
diff --git a/ports/cef/interfaces/cef_zip_reader.rs b/ports/cef/interfaces/cef_zip_reader.rs
index fa68644de81..36af7b19611 100644
--- a/ports/cef/interfaces/cef_zip_reader.rs
+++ b/ports/cef/interfaces/cef_zip_reader.rs
@@ -164,8 +164,7 @@ pub struct CefZipReader {
 impl Clone for CefZipReader {
   fn clone(&self) -> CefZipReader{
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
       }
       CefZipReader {
@@ -178,8 +177,7 @@ impl Clone for CefZipReader {
 impl Drop for CefZipReader {
   fn drop(&mut self) {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
       }
     }
@@ -194,8 +192,7 @@ impl CefZipReader {
   }
 
   pub unsafe fn from_c_object_addref(c_object: *mut cef_zip_reader_t) -> CefZipReader {
-    if !c_object.is_null() &&
-        c_object as usize != mem::POST_DROP_USIZE {
+    if !c_object.is_null() {
       ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
     }
     CefZipReader {
@@ -209,8 +206,7 @@ impl CefZipReader {
 
   pub fn c_object_addrefed(&self) -> *mut cef_zip_reader_t {
     unsafe {
-      if !self.c_object.is_null() &&
-          self.c_object as usize != mem::POST_DROP_USIZE {
+      if !self.c_object.is_null() {
         eutil::add_ref(self.c_object as *mut types::cef_base_t);
       }
       self.c_object
@@ -218,10 +214,10 @@ impl CefZipReader {
   }
 
   pub fn is_null_cef_object(&self) -> bool {
-    self.c_object.is_null() || self.c_object as usize == mem::POST_DROP_USIZE
+    self.c_object.is_null()
   }
   pub fn is_not_null_cef_object(&self) -> bool {
-    !self.c_object.is_null() && self.c_object as usize != mem::POST_DROP_USIZE
+    !self.c_object.is_null()
   }
 
   //
@@ -229,8 +225,7 @@ impl CefZipReader {
   // cursor position was set successfully.
   //
   pub fn move_to_first_file(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -245,8 +240,7 @@ impl CefZipReader {
   // cursor position was set successfully.
   //
   pub fn move_to_next_file(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -263,8 +257,7 @@ impl CefZipReader {
   //
   pub fn move_to_file(&self, fileName: &[u16],
       caseSensitive: libc::c_int) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -281,8 +274,7 @@ impl CefZipReader {
   // occurs on the correct thread.
   //
   pub fn close(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -300,8 +292,7 @@ impl CefZipReader {
   //
   // The resulting string must be freed by calling cef_string_userfree_free().
   pub fn get_file_name(&self) -> String {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -315,8 +306,7 @@ impl CefZipReader {
   // Returns the uncompressed size of the file.
   //
   pub fn get_file_size(&self) -> i64 {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -330,8 +320,7 @@ impl CefZipReader {
   // Returns the last modified timestamp for the file.
   //
   pub fn get_file_last_modified(&self) -> types::cef_time_t {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -346,8 +335,7 @@ impl CefZipReader {
   // optionally be specified.
   //
   pub fn open_file(&self, password: &[u16]) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -362,8 +350,7 @@ impl CefZipReader {
   // Closes the file.
   //
   pub fn close_file(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -379,8 +366,7 @@ impl CefZipReader {
   //
   pub fn read_file(&self, buffer: &mut (),
       bufferSize: libc::size_t) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -396,8 +382,7 @@ impl CefZipReader {
   // Returns the current offset in the uncompressed file contents.
   //
   pub fn tell(&self) -> i64 {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -411,8 +396,7 @@ impl CefZipReader {
   // Returns true (1) if at end of the file contents.
   //
   pub fn eof(&self) -> libc::c_int {
-    if self.c_object.is_null() ||
-       self.c_object as usize == mem::POST_DROP_USIZE {
+    if self.c_object.is_null() {
       panic!("called a CEF method on a null object")
     }
     unsafe {
@@ -452,8 +436,7 @@ impl CefWrap<*mut cef_zip_reader_t> for Option<CefZipReader> {
     }
   }
   unsafe fn to_rust(c_object: *mut cef_zip_reader_t) -> Option<CefZipReader> {
-    if c_object.is_null() &&
-       c_object as usize != mem::POST_DROP_USIZE {
+    if c_object.is_null() {
       None
     } else {
       Some(CefZipReader::from_c_object_addref(c_object))
diff --git a/ports/cef/lib.rs b/ports/cef/lib.rs
index 9e6c792e15c..eb7543b3d7c 100644
--- a/ports/cef/lib.rs
+++ b/ports/cef/lib.rs
@@ -4,12 +4,10 @@
 
 #![feature(box_syntax)]
 #![feature(core_intrinsics)]
-#![feature(filling_drop)]
 #![feature(link_args)]
 #![feature(plugin)]
 #![feature(try_borrow)]
 #![feature(unicode)]
-#![feature(unsafe_no_drop_flag)]
 
 #![allow(non_camel_case_types)]
 
diff --git a/ports/geckolib/Cargo.lock b/ports/geckolib/Cargo.lock
index e890e17e67a..1c1b3788abe 100644
--- a/ports/geckolib/Cargo.lock
+++ b/ports/geckolib/Cargo.lock
@@ -327,7 +327,7 @@ dependencies = [
  "matches 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "quickersort 2.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "smallvec 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)",
- "string_cache 0.2.24 (registry+https://github.com/rust-lang/crates.io-index)",
+ "string_cache 0.2.25 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -342,7 +342,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "string_cache"
-version = "0.2.24"
+version = "0.2.25"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "debug_unreachable 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
diff --git a/rust-nightly-date b/rust-nightly-date
index 02e42b37add..d8db53481c0 100644
--- a/rust-nightly-date
+++ b/rust-nightly-date
@@ -1 +1 @@
-2016-08-23
+2016-08-27
diff --git a/tests/unit/script/size_of.rs b/tests/unit/script/size_of.rs
index b30304d5dac..96981ca001f 100644
--- a/tests/unit/script/size_of.rs
+++ b/tests/unit/script/size_of.rs
@@ -39,11 +39,11 @@ macro_rules! sizeof_checker (
 
 // Update the sizes here
 sizeof_checker!(size_event_target, EventTarget, 40);
-sizeof_checker!(size_node, Node, 160);
-sizeof_checker!(size_element, Element, 336);
-sizeof_checker!(size_htmlelement, HTMLElement, 352);
-sizeof_checker!(size_div, HTMLDivElement, 352);
-sizeof_checker!(size_span, HTMLSpanElement, 352);
-sizeof_checker!(size_text, Text, 192);
-sizeof_checker!(size_characterdata, CharacterData, 192);
+sizeof_checker!(size_node, Node, 152);
+sizeof_checker!(size_element, Element, 328);
+sizeof_checker!(size_htmlelement, HTMLElement, 344);
+sizeof_checker!(size_div, HTMLDivElement, 344);
+sizeof_checker!(size_span, HTMLSpanElement, 344);
+sizeof_checker!(size_text, Text, 184);
+sizeof_checker!(size_characterdata, CharacterData, 184);
 sizeof_checker!(size_servothreadsafelayoutnode, ServoThreadSafeLayoutNode, 16);
diff --git a/tests/unit/style/Cargo.toml b/tests/unit/style/Cargo.toml
index 85eeb3b4466..138ec1472fe 100644
--- a/tests/unit/style/Cargo.toml
+++ b/tests/unit/style/Cargo.toml
@@ -15,7 +15,7 @@ cssparser = {version = "0.5.7", features = ["heap_size"]}
 euclid = "0.10.1"
 rustc-serialize = "0.3"
 selectors = {version = "0.11", features = ["heap_size"]}
-string_cache = {version = "0.2.23", features = ["heap_size"]}
+string_cache = {version = "0.2.25", features = ["heap_size"]}
 style = {path = "../../../components/style"}
 style_traits = {path = "../../../components/style_traits"}
 url = {version = "1.2", features = ["heap_size"]}