ports/cef: Use the CEF translator tool to generate the full set of CEF

bindings.

This replaces hand-implemented CEF bindings with proper Rust wrappers
automatically generated from the C++ headers. This means that, whenever
CEF's C++ headers change, we can easily generate both the appropriate C
API and the appropriate Rust API. It eliminates much of the hand-written
unsafe code within the CEF port, because the CEF translator tool now
knows how to generate Rust smart pointer wrappers for each class that
corrently perform reference counting.

Additionally, this commit adds utility macros (located in `macros.rs`)
that make it easier to correctly expose Rust objects as CEF objects.
They handle the marshaling of objects between Rust and CEF properly.
The net result of this is that you can write mostly-natural-looking Rust
in the CEF port and interact with it with a natural-looking C++ API on
the embedding side.

This setup relies on the branch of CEF located here:

    https://github.com/pcwalton/chromium-embedded-framework

To regenerate, follow the instructions in `ports/cef/README.md`. For
convenience, and because I don't anticipate the API to change much, I
have vendored in all of the appropriate interfaces.

ports/cef/interfaces/cef_web_plugin.rs

@@ -0,0 +1,544 @@
+// Copyright (c) 2014 Marshall A. Greenblatt. All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//    * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//    * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//    * Neither the name of Google Inc. nor the name Chromium Embedded
+// Framework nor the names of its contributors may be used to endorse
+// or promote products derived from this software without specific prior
+// written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+// ---------------------------------------------------------------------------
+//
+// This file was generated by the CEF translator tool and should not be edited
+// by hand. See the translator.README.txt file in the tools directory for
+// more information.
+//
+
+#![allow(non_snake_case, unused_imports)]
+
+use eutil;
+use interfaces;
+use types;
+use wrappers::CefWrap;
+
+use libc;
+use std::collections::HashMap;
+use std::ptr;
+
+//
+// Information about a specific web plugin.
+//
+#[repr(C)]
+pub struct _cef_web_plugin_info_t {
+  //
+  // Base structure.
+  //
+  pub base: types::cef_base_t,
+
+  //
+  // Returns the plugin name (i.e. Flash).
+  //
+  // The resulting string must be freed by calling cef_string_userfree_free().
+  pub get_name: Option<extern "C" fn(
+      this: *mut cef_web_plugin_info_t) -> types::cef_string_userfree_t>,
+
+  //
+  // Returns the plugin file path (DLL/bundle/library).
+  //
+  // The resulting string must be freed by calling cef_string_userfree_free().
+  pub get_path: Option<extern "C" fn(
+      this: *mut cef_web_plugin_info_t) -> types::cef_string_userfree_t>,
+
+  //
+  // Returns the version of the plugin (may be OS-specific).
+  //
+  // The resulting string must be freed by calling cef_string_userfree_free().
+  pub get_version: Option<extern "C" fn(
+      this: *mut cef_web_plugin_info_t) -> types::cef_string_userfree_t>,
+
+  //
+  // Returns a description of the plugin from the version information.
+  //
+  // The resulting string must be freed by calling cef_string_userfree_free().
+  pub get_description: Option<extern "C" fn(
+      this: *mut cef_web_plugin_info_t) -> types::cef_string_userfree_t>,
+
+  //
+  // The reference count. This will only be present for Rust instances!
+  //
+  ref_count: uint,
+
+  //
+  // Extra data. This will only be present for Rust instances!
+  //
+  pub extra: u8,
+} 
+
+pub type cef_web_plugin_info_t = _cef_web_plugin_info_t;
+
+
+//
+// Information about a specific web plugin.
+//
+pub struct CefWebPluginInfo {
+  c_object: *mut cef_web_plugin_info_t,
+}
+
+impl Clone for CefWebPluginInfo {
+  fn clone(&self) -> CefWebPluginInfo{
+    unsafe {
+      if !self.c_object.is_null() {
+        ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
+      }
+      CefWebPluginInfo {
+        c_object: self.c_object,
+      }
+    }
+  }
+}
+
+impl Drop for CefWebPluginInfo {
+  fn drop(&mut self) {
+    unsafe {
+      if !self.c_object.is_null() {
+        ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
+      }
+    }
+  }
+}
+
+impl CefWebPluginInfo {
+  pub unsafe fn from_c_object(c_object: *mut cef_web_plugin_info_t) -> CefWebPluginInfo {
+    CefWebPluginInfo {
+      c_object: c_object,
+    }
+  }
+
+  pub unsafe fn from_c_object_addref(c_object: *mut cef_web_plugin_info_t) -> CefWebPluginInfo {
+    if !c_object.is_null() {
+      ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
+    }
+    CefWebPluginInfo {
+      c_object: c_object,
+    }
+  }
+
+  pub fn c_object(&self) -> *mut cef_web_plugin_info_t {
+    self.c_object
+  }
+
+  pub fn c_object_addrefed(&self) -> *mut cef_web_plugin_info_t {
+    unsafe {
+      if !self.c_object.is_null() {
+        eutil::add_ref(self.c_object as *mut types::cef_base_t);
+      }
+      self.c_object
+    }
+  }
+
+  pub fn is_null_cef_object(&self) -> bool {
+    self.c_object.is_null()
+  }
+  pub fn is_not_null_cef_object(&self) -> bool {
+    !self.c_object.is_null()
+  }
+
+  //
+  // Returns the plugin name (i.e. Flash).
+  //
+  // The resulting string must be freed by calling cef_string_userfree_free().
+  pub fn get_name(&self) -> String {
+    if self.c_object.is_null() {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).get_name.unwrap())(
+          self.c_object))
+    }
+  }
+
+  //
+  // Returns the plugin file path (DLL/bundle/library).
+  //
+  // The resulting string must be freed by calling cef_string_userfree_free().
+  pub fn get_path(&self) -> String {
+    if self.c_object.is_null() {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).get_path.unwrap())(
+          self.c_object))
+    }
+  }
+
+  //
+  // Returns the version of the plugin (may be OS-specific).
+  //
+  // The resulting string must be freed by calling cef_string_userfree_free().
+  pub fn get_version(&self) -> String {
+    if self.c_object.is_null() {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).get_version.unwrap())(
+          self.c_object))
+    }
+  }
+
+  //
+  // Returns a description of the plugin from the version information.
+  //
+  // The resulting string must be freed by calling cef_string_userfree_free().
+  pub fn get_description(&self) -> String {
+    if self.c_object.is_null() {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).get_description.unwrap())(
+          self.c_object))
+    }
+  }
+} 
+
+impl CefWrap<*mut cef_web_plugin_info_t> for CefWebPluginInfo {
+  fn to_c(rust_object: CefWebPluginInfo) -> *mut cef_web_plugin_info_t {
+    rust_object.c_object_addrefed()
+  }
+  unsafe fn to_rust(c_object: *mut cef_web_plugin_info_t) -> CefWebPluginInfo {
+    CefWebPluginInfo::from_c_object_addref(c_object)
+  }
+}
+impl CefWrap<*mut cef_web_plugin_info_t> for Option<CefWebPluginInfo> {
+  fn to_c(rust_object: Option<CefWebPluginInfo>) -> *mut cef_web_plugin_info_t {
+    match rust_object {
+      None => ptr::null_mut(),
+      Some(rust_object) => rust_object.c_object_addrefed(),
+    }
+  }
+  unsafe fn to_rust(c_object: *mut cef_web_plugin_info_t) -> Option<CefWebPluginInfo> {
+    if c_object.is_null() {
+      None
+    } else {
+      Some(CefWebPluginInfo::from_c_object_addref(c_object))
+    }
+  }
+}
+
+
+//
+// Structure to implement for visiting web plugin information. The functions of
+// this structure will be called on the browser process UI thread.
+//
+#[repr(C)]
+pub struct _cef_web_plugin_info_visitor_t {
+  //
+  // Base structure.
+  //
+  pub base: types::cef_base_t,
+
+  //
+  // Method that will be called once for each plugin. |count| is the 0-based
+  // index for the current plugin. |total| is the total number of plugins.
+  // Return false (0) to stop visiting plugins. This function may never be
+  // called if no plugins are found.
+  //
+  pub visit: Option<extern "C" fn(this: *mut cef_web_plugin_info_visitor_t,
+      info: *mut interfaces::cef_web_plugin_info_t, count: libc::c_int,
+      total: libc::c_int) -> libc::c_int>,
+
+  //
+  // The reference count. This will only be present for Rust instances!
+  //
+  ref_count: uint,
+
+  //
+  // Extra data. This will only be present for Rust instances!
+  //
+  pub extra: u8,
+} 
+
+pub type cef_web_plugin_info_visitor_t = _cef_web_plugin_info_visitor_t;
+
+
+//
+// Structure to implement for visiting web plugin information. The functions of
+// this structure will be called on the browser process UI thread.
+//
+pub struct CefWebPluginInfoVisitor {
+  c_object: *mut cef_web_plugin_info_visitor_t,
+}
+
+impl Clone for CefWebPluginInfoVisitor {
+  fn clone(&self) -> CefWebPluginInfoVisitor{
+    unsafe {
+      if !self.c_object.is_null() {
+        ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
+      }
+      CefWebPluginInfoVisitor {
+        c_object: self.c_object,
+      }
+    }
+  }
+}
+
+impl Drop for CefWebPluginInfoVisitor {
+  fn drop(&mut self) {
+    unsafe {
+      if !self.c_object.is_null() {
+        ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
+      }
+    }
+  }
+}
+
+impl CefWebPluginInfoVisitor {
+  pub unsafe fn from_c_object(c_object: *mut cef_web_plugin_info_visitor_t) -> CefWebPluginInfoVisitor {
+    CefWebPluginInfoVisitor {
+      c_object: c_object,
+    }
+  }
+
+  pub unsafe fn from_c_object_addref(c_object: *mut cef_web_plugin_info_visitor_t) -> CefWebPluginInfoVisitor {
+    if !c_object.is_null() {
+      ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
+    }
+    CefWebPluginInfoVisitor {
+      c_object: c_object,
+    }
+  }
+
+  pub fn c_object(&self) -> *mut cef_web_plugin_info_visitor_t {
+    self.c_object
+  }
+
+  pub fn c_object_addrefed(&self) -> *mut cef_web_plugin_info_visitor_t {
+    unsafe {
+      if !self.c_object.is_null() {
+        eutil::add_ref(self.c_object as *mut types::cef_base_t);
+      }
+      self.c_object
+    }
+  }
+
+  pub fn is_null_cef_object(&self) -> bool {
+    self.c_object.is_null()
+  }
+  pub fn is_not_null_cef_object(&self) -> bool {
+    !self.c_object.is_null()
+  }
+
+  //
+  // Method that will be called once for each plugin. |count| is the 0-based
+  // index for the current plugin. |total| is the total number of plugins.
+  // Return false (0) to stop visiting plugins. This function may never be
+  // called if no plugins are found.
+  //
+  pub fn visit(&self, info: interfaces::CefWebPluginInfo, count: libc::c_int,
+      total: libc::c_int) -> libc::c_int {
+    if self.c_object.is_null() {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).visit.unwrap())(
+          self.c_object,
+          CefWrap::to_c(info),
+          CefWrap::to_c(count),
+          CefWrap::to_c(total)))
+    }
+  }
+} 
+
+impl CefWrap<*mut cef_web_plugin_info_visitor_t> for CefWebPluginInfoVisitor {
+  fn to_c(rust_object: CefWebPluginInfoVisitor) -> *mut cef_web_plugin_info_visitor_t {
+    rust_object.c_object_addrefed()
+  }
+  unsafe fn to_rust(c_object: *mut cef_web_plugin_info_visitor_t) -> CefWebPluginInfoVisitor {
+    CefWebPluginInfoVisitor::from_c_object_addref(c_object)
+  }
+}
+impl CefWrap<*mut cef_web_plugin_info_visitor_t> for Option<CefWebPluginInfoVisitor> {
+  fn to_c(rust_object: Option<CefWebPluginInfoVisitor>) -> *mut cef_web_plugin_info_visitor_t {
+    match rust_object {
+      None => ptr::null_mut(),
+      Some(rust_object) => rust_object.c_object_addrefed(),
+    }
+  }
+  unsafe fn to_rust(c_object: *mut cef_web_plugin_info_visitor_t) -> Option<CefWebPluginInfoVisitor> {
+    if c_object.is_null() {
+      None
+    } else {
+      Some(CefWebPluginInfoVisitor::from_c_object_addref(c_object))
+    }
+  }
+}
+
+
+//
+// Structure to implement for receiving unstable plugin information. The
+// functions of this structure will be called on the browser process IO thread.
+//
+#[repr(C)]
+pub struct _cef_web_plugin_unstable_callback_t {
+  //
+  // Base structure.
+  //
+  pub base: types::cef_base_t,
+
+  //
+  // Method that will be called for the requested plugin. |unstable| will be
+  // true (1) if the plugin has reached the crash count threshold of 3 times in
+  // 120 seconds.
+  //
+  pub is_unstable: Option<extern "C" fn(
+      this: *mut cef_web_plugin_unstable_callback_t,
+      path: *const types::cef_string_t, unstable: libc::c_int) -> ()>,
+
+  //
+  // The reference count. This will only be present for Rust instances!
+  //
+  ref_count: uint,
+
+  //
+  // Extra data. This will only be present for Rust instances!
+  //
+  pub extra: u8,
+} 
+
+pub type cef_web_plugin_unstable_callback_t = _cef_web_plugin_unstable_callback_t;
+
+
+//
+// Structure to implement for receiving unstable plugin information. The
+// functions of this structure will be called on the browser process IO thread.
+//
+pub struct CefWebPluginUnstableCallback {
+  c_object: *mut cef_web_plugin_unstable_callback_t,
+}
+
+impl Clone for CefWebPluginUnstableCallback {
+  fn clone(&self) -> CefWebPluginUnstableCallback{
+    unsafe {
+      if !self.c_object.is_null() {
+        ((*self.c_object).base.add_ref.unwrap())(&mut (*self.c_object).base);
+      }
+      CefWebPluginUnstableCallback {
+        c_object: self.c_object,
+      }
+    }
+  }
+}
+
+impl Drop for CefWebPluginUnstableCallback {
+  fn drop(&mut self) {
+    unsafe {
+      if !self.c_object.is_null() {
+        ((*self.c_object).base.release.unwrap())(&mut (*self.c_object).base);
+      }
+    }
+  }
+}
+
+impl CefWebPluginUnstableCallback {
+  pub unsafe fn from_c_object(c_object: *mut cef_web_plugin_unstable_callback_t) -> CefWebPluginUnstableCallback {
+    CefWebPluginUnstableCallback {
+      c_object: c_object,
+    }
+  }
+
+  pub unsafe fn from_c_object_addref(c_object: *mut cef_web_plugin_unstable_callback_t) -> CefWebPluginUnstableCallback {
+    if !c_object.is_null() {
+      ((*c_object).base.add_ref.unwrap())(&mut (*c_object).base);
+    }
+    CefWebPluginUnstableCallback {
+      c_object: c_object,
+    }
+  }
+
+  pub fn c_object(&self) -> *mut cef_web_plugin_unstable_callback_t {
+    self.c_object
+  }
+
+  pub fn c_object_addrefed(&self) -> *mut cef_web_plugin_unstable_callback_t {
+    unsafe {
+      if !self.c_object.is_null() {
+        eutil::add_ref(self.c_object as *mut types::cef_base_t);
+      }
+      self.c_object
+    }
+  }
+
+  pub fn is_null_cef_object(&self) -> bool {
+    self.c_object.is_null()
+  }
+  pub fn is_not_null_cef_object(&self) -> bool {
+    !self.c_object.is_null()
+  }
+
+  //
+  // Method that will be called for the requested plugin. |unstable| will be
+  // true (1) if the plugin has reached the crash count threshold of 3 times in
+  // 120 seconds.
+  //
+  pub fn is_unstable(&self, path: &str, unstable: libc::c_int) -> () {
+    if self.c_object.is_null() {
+      panic!("called a CEF method on a null object")
+    }
+    unsafe {
+      CefWrap::to_rust(
+        ((*self.c_object).is_unstable.unwrap())(
+          self.c_object,
+          CefWrap::to_c(path),
+          CefWrap::to_c(unstable)))
+    }
+  }
+} 
+
+impl CefWrap<*mut cef_web_plugin_unstable_callback_t> for CefWebPluginUnstableCallback {
+  fn to_c(rust_object: CefWebPluginUnstableCallback) -> *mut cef_web_plugin_unstable_callback_t {
+    rust_object.c_object_addrefed()
+  }
+  unsafe fn to_rust(c_object: *mut cef_web_plugin_unstable_callback_t) -> CefWebPluginUnstableCallback {
+    CefWebPluginUnstableCallback::from_c_object_addref(c_object)
+  }
+}
+impl CefWrap<*mut cef_web_plugin_unstable_callback_t> for Option<CefWebPluginUnstableCallback> {
+  fn to_c(rust_object: Option<CefWebPluginUnstableCallback>) -> *mut cef_web_plugin_unstable_callback_t {
+    match rust_object {
+      None => ptr::null_mut(),
+      Some(rust_object) => rust_object.c_object_addrefed(),
+    }
+  }
+  unsafe fn to_rust(c_object: *mut cef_web_plugin_unstable_callback_t) -> Option<CefWebPluginUnstableCallback> {
+    if c_object.is_null() {
+      None
+    } else {
+      Some(CefWebPluginUnstableCallback::from_c_object_addref(c_object))
+    }
+  }
+}
+