diff --git a/components/script/Cargo.toml b/components/script/Cargo.toml
index f0dd201bf37..709ced84779 100644
--- a/components/script/Cargo.toml
+++ b/components/script/Cargo.toml
@@ -79,6 +79,8 @@ libc = "0.2"
 log = "0.3"
 num = "0.1.24"
 rand = "0.3"
+phf = "0.7.13"
+phf_macros = "0.7.13"
 ref_slice = "0.1.0"
 rustc-serialize = "0.3"
 selectors = {version = "0.5", features = ["heap_size"]}
diff --git a/components/script/dom/bindings/codegen/CodegenRust.py b/components/script/dom/bindings/codegen/CodegenRust.py
index 27272370cc1..56144485ab6 100644
--- a/components/script/dom/bindings/codegen/CodegenRust.py
+++ b/components/script/dom/bindings/codegen/CodegenRust.py
@@ -1768,17 +1768,21 @@ class CGDOMJSClass(CGThing):
     def define(self):
         args = {
             "domClass": DOMClass(self.descriptor),
+            "enumerateHook": "None",
             "finalizeHook": FINALIZE_HOOK_NAME,
             "flags": "0",
             "name": str_to_const_array(self.descriptor.interface.identifier.name),
             "outerObjectHook": self.descriptor.outerObjectHook,
+            "resolveHook": "None",
             "slots": "1",
             "traceHook": TRACE_HOOK_NAME,
         }
         if self.descriptor.isGlobal():
             assert not self.descriptor.weakReferenceable
+            args["enumerateHook"] = "Some(enumerate_global)"
             args["flags"] = "JSCLASS_IS_GLOBAL | JSCLASS_DOM_GLOBAL"
             args["slots"] = "JSCLASS_GLOBAL_SLOT_COUNT + 1"
+            args["resolveHook"] = "Some(resolve_global)"
             args["traceHook"] = "js::jsapi::JS_GlobalObjectTraceHook"
         elif self.descriptor.weakReferenceable:
             args["slots"] = "2"
@@ -1793,8 +1797,8 @@ static Class: DOMJSClass = DOMJSClass {
         delProperty: None,
         getProperty: None,
         setProperty: None,
-        enumerate: None,
-        resolve: None,
+        enumerate: %(enumerateHook)s,
+        resolve: %(resolveHook)s,
         convert: None,
         finalize: Some(%(finalizeHook)s),
         call: None,
@@ -2276,11 +2280,8 @@ JS_SetPrototype(cx, obj.handle(), proto.handle());
 %(copyUnforgeable)s
 (*raw).init_reflector(obj.ptr);
 
-let ret = Root::from_ref(&*raw);
-
-RegisterBindings::Register(cx, obj.handle());
-
-ret""" % {'copyUnforgeable': unforgeable, 'createObject': create})
+Root::from_ref(&*raw)\
+""" % {'copyUnforgeable': unforgeable, 'createObject': create})
 
 
 class CGIDLInterface(CGThing):
@@ -2375,9 +2376,8 @@ class CGCreateInterfaceObjectsMethod(CGAbstractMethod):
     properties should be a PropertyArrays instance.
     """
     def __init__(self, descriptor, properties):
-        args = [Argument('*mut JSContext', 'cx'), Argument('HandleObject', 'global')]
-        if not descriptor.interface.isCallback():
-            args.append(Argument('*mut ProtoOrIfaceArray', 'cache'))
+        args = [Argument('*mut JSContext', 'cx'), Argument('HandleObject', 'global'),
+                Argument('*mut ProtoOrIfaceArray', 'cache')]
         CGAbstractMethod.__init__(self, descriptor, 'CreateInterfaceObjects', 'void', args,
                                   unsafe=True)
         self.properties = properties
@@ -2387,7 +2387,14 @@ class CGCreateInterfaceObjectsMethod(CGAbstractMethod):
         if self.descriptor.interface.isCallback():
             assert not self.descriptor.interface.ctor() and self.descriptor.interface.hasConstants()
             return CGGeneric("""\
-create_callback_interface_object(cx, global, sConstants, %s);""" % str_to_const_array(name))
+let mut interface = RootedObject::new(cx, ptr::null_mut());
+create_callback_interface_object(cx, global, sConstants, %(name)s, interface.handle_mut());
+assert!(!interface.ptr.is_null());
+(*cache)[PrototypeList::Constructor::%(id)s as usize] = interface.ptr;
+if <*mut JSObject>::needs_post_barrier(interface.ptr) {
+    <*mut JSObject>::post_barrier((*cache).as_mut_ptr().offset(PrototypeList::Constructor::%(id)s as isize));
+}
+""" % {"id": name, "name": str_to_const_array(name)})
 
         if len(self.descriptor.prototypeChain) == 1:
             if self.descriptor.interface.getExtendedAttribute("ExceptionClass"):
@@ -2668,14 +2675,14 @@ class CGDefineDOMInterfaceMethod(CGAbstractMethod):
 
     def definition_body(self):
         if self.descriptor.interface.isCallback():
-            code = "CreateInterfaceObjects(cx, global);"
+            function = "GetConstructorObject"
         else:
-            code = """\
+            function = "GetProtoObject"
+        return CGGeneric("""\
+assert!(!global.get().is_null());
 let mut proto = RootedObject::new(cx, ptr::null_mut());
-GetProtoObject(cx, global, proto.handle_mut());
-assert!(!proto.ptr.is_null());
-"""
-        return CGGeneric("assert!(!global.get().is_null());\n" + code)
+%s(cx, global, proto.handle_mut());
+assert!(!proto.ptr.is_null());""" % function)
 
 
 def needCx(returnType, arguments, considerTypes):
@@ -4952,7 +4959,8 @@ class CGDescriptor(CGThing):
         cgThings = []
         if not descriptor.interface.isCallback():
             cgThings.append(CGGetProtoObjectMethod(descriptor))
-        if descriptor.interface.hasInterfaceObject() and descriptor.hasDescendants():
+        if (descriptor.interface.hasInterfaceObject() and
+                descriptor.shouldHaveGetConstructorObjectMethod()):
             cgThings.append(CGGetConstructorObjectMethod(descriptor))
 
         for m in descriptor.interface.members:
@@ -5277,23 +5285,6 @@ class CGDictionary(CGThing):
         return deps
 
 
-class CGRegisterProtos(CGAbstractMethod):
-    def __init__(self, config):
-        arguments = [
-            Argument('*mut JSContext', 'cx'),
-            Argument('HandleObject', 'global'),
-        ]
-        CGAbstractMethod.__init__(self, None, 'Register', 'void', arguments,
-                                  unsafe=False, pub=True)
-        self.config = config
-
-    def definition_body(self):
-        return CGList([
-            CGGeneric("codegen::Bindings::%sBinding::DefineDOMInterface(cx, global);" % desc.name)
-            for desc in self.config.getDescriptors(hasInterfaceObject=True, register=True)
-        ], "\n")
-
-
 class CGRegisterProxyHandlersMethod(CGAbstractMethod):
     def __init__(self, descriptors):
         docs = "Create the global vtables used by the generated DOM bindings to implement JS proxies."
@@ -5436,12 +5427,12 @@ class CGBindingRoot(CGThing):
             'dom::bindings::utils::{DOMClass, DOMJSClass}',
             'dom::bindings::utils::{DOM_PROTO_UNFORGEABLE_HOLDER_SLOT, JSCLASS_DOM_GLOBAL}',
             'dom::bindings::utils::{ProtoOrIfaceArray, create_dom_global}',
-            'dom::bindings::utils::{finalize_global, find_enum_string_index, generic_getter}',
-            'dom::bindings::utils::{generic_lenient_getter, generic_lenient_setter}',
+            'dom::bindings::utils::{enumerate_global, finalize_global, find_enum_string_index}',
+            'dom::bindings::utils::{generic_getter, generic_lenient_getter, generic_lenient_setter}',
             'dom::bindings::utils::{generic_method, generic_setter, get_array_index_from_id}',
             'dom::bindings::utils::{get_dictionary_property, get_property_on_prototype}',
             'dom::bindings::utils::{get_proto_or_iface_array, has_property_on_prototype}',
-            'dom::bindings::utils::{is_platform_object, set_dictionary_property}',
+            'dom::bindings::utils::{is_platform_object, resolve_global, set_dictionary_property}',
             'dom::bindings::utils::{throwing_constructor, trace_global}',
             'dom::bindings::trace::{JSTraceable, RootedTraceable}',
             'dom::bindings::callback::{CallbackContainer,CallbackInterface,CallbackFunction}',
@@ -6084,12 +6075,44 @@ class GlobalGenRoots():
     call the appropriate define/declare method.
     """
 
+    @staticmethod
+    def InterfaceObjectMap(config):
+        mods = [
+            "dom::bindings::codegen",
+            "js::jsapi::{HandleObject, JSContext}",
+            "phf",
+        ]
+        imports = CGList([CGGeneric("use %s;" % mod) for mod in mods], "\n")
+
+        pairs = []
+        for d in config.getDescriptors(hasInterfaceObject=True):
+            binding = toBindingNamespace(d.name)
+            pairs.append((d.name, binding))
+            for ctor in d.interface.namedConstructors:
+                pairs.append((ctor.identifier.name, binding))
+        pairs.sort(key=operator.itemgetter(0))
+        mappings = [
+            CGGeneric('b"%s" => codegen::Bindings::%s::DefineDOMInterface as fn(_, _),' % pair)
+            for pair in pairs
+        ]
+        mapType = "phf::Map<&'static [u8], fn(*mut JSContext, HandleObject)>"
+        phf = CGWrapper(
+            CGIndenter(CGList(mappings, "\n")),
+            pre="pub static MAP: %s = phf_map! {\n" % mapType,
+            post="\n};\n")
+
+        return CGList([
+            CGGeneric(AUTOGENERATED_WARNING_COMMENT),
+            CGList([imports, phf], "\n\n")
+        ])
+
     @staticmethod
     def PrototypeList(config):
         # Prototype ID enum.
         interfaces = config.getDescriptors(isCallback=False)
         protos = [d.name for d in interfaces]
-        constructors = [d.name for d in interfaces if d.hasDescendants()]
+        constructors = [d.name for d in config.getDescriptors(hasInterfaceObject=True)
+                        if d.shouldHaveGetConstructorObjectMethod()]
         proxies = [d.name for d in config.getDescriptors(proxy=True)]
 
         return CGList([
@@ -6115,15 +6138,12 @@ class GlobalGenRoots():
     def RegisterBindings(config):
         # TODO - Generate the methods we want
         code = CGList([
-            CGRegisterProtos(config),
             CGRegisterProxyHandlers(config),
         ], "\n")
 
         return CGImports(code, [], [], [
             'dom::bindings::codegen',
             'dom::bindings::codegen::PrototypeList::Proxies',
-            'js::jsapi::JSContext',
-            'js::jsapi::HandleObject',
             'libc',
         ], ignored_warnings=[])
 
diff --git a/components/script/dom/bindings/codegen/Configuration.py b/components/script/dom/bindings/codegen/Configuration.py
index 762998b91ac..c634665c410 100644
--- a/components/script/dom/bindings/codegen/Configuration.py
+++ b/components/script/dom/bindings/codegen/Configuration.py
@@ -345,6 +345,10 @@ class Descriptor(DescriptorProvider):
         return (self.interface.getUserData("hasConcreteDescendant", False) or
                 self.interface.getUserData("hasProxyDescendant", False))
 
+    def shouldHaveGetConstructorObjectMethod(self):
+        assert self.interface.hasInterfaceObject()
+        return self.interface.isCallback() or self.hasDescendants()
+
     def isGlobal(self):
         """
         Returns true if this is the primary interface for a global object
diff --git a/components/script/dom/bindings/codegen/GlobalGen.py b/components/script/dom/bindings/codegen/GlobalGen.py
index f4210331e0e..72a2faa71e4 100644
--- a/components/script/dom/bindings/codegen/GlobalGen.py
+++ b/components/script/dom/bindings/codegen/GlobalGen.py
@@ -62,6 +62,7 @@ def main():
     to_generate = [
         ('PrototypeList', 'PrototypeList.rs'),
         ('RegisterBindings', 'RegisterBindings.rs'),
+        ('InterfaceObjectMap', 'InterfaceObjectMap.rs'),
         ('InterfaceTypes', 'InterfaceTypes.rs'),
         ('InheritTypes', 'InheritTypes.rs'),
         ('Bindings', os.path.join('Bindings', 'mod.rs')),
diff --git a/components/script/dom/bindings/interface.rs b/components/script/dom/bindings/interface.rs
index bb98c06f63a..a5bc3ec513c 100644
--- a/components/script/dom/bindings/interface.rs
+++ b/components/script/dom/bindings/interface.rs
@@ -178,13 +178,14 @@ pub unsafe fn create_callback_interface_object(
         cx: *mut JSContext,
         receiver: HandleObject,
         constants: &'static [ConstantSpec],
-        name: &'static [u8]) {
+        name: &'static [u8],
+        rval: MutableHandleObject) {
     assert!(!constants.is_empty());
-    let interface_object = RootedObject::new(cx, JS_NewObject(cx, ptr::null()));
-    assert!(!interface_object.ptr.is_null());
-    define_constants(cx, interface_object.handle(), constants);
-    define_name(cx, interface_object.handle(), name);
-    define_on_global_object(cx, receiver, name, interface_object.handle());
+    rval.set(JS_NewObject(cx, ptr::null()));
+    assert!(!rval.ptr.is_null());
+    define_constants(cx, rval.handle(), constants);
+    define_name(cx, rval.handle(), name);
+    define_on_global_object(cx, receiver, name, rval.handle());
 }
 
 /// Create the interface prototype object of a non-callback interface.
diff --git a/components/script/dom/bindings/mod.rs b/components/script/dom/bindings/mod.rs
index 602e24fe2e0..160141f76e4 100644
--- a/components/script/dom/bindings/mod.rs
+++ b/components/script/dom/bindings/mod.rs
@@ -159,6 +159,9 @@ pub mod codegen {
     pub mod Bindings {
         include!(concat!(env!("OUT_DIR"), "/Bindings/mod.rs"));
     }
+    pub mod InterfaceObjectMap {
+        include!(concat!(env!("OUT_DIR"), "/InterfaceObjectMap.rs"));
+    }
     pub mod InterfaceTypes {
         include!(concat!(env!("OUT_DIR"), "/InterfaceTypes.rs"));
     }
diff --git a/components/script/dom/bindings/utils.rs b/components/script/dom/bindings/utils.rs
index adc96c45305..2b4e5ee5ae0 100644
--- a/components/script/dom/bindings/utils.rs
+++ b/components/script/dom/bindings/utils.rs
@@ -4,6 +4,7 @@
 
 //! Various utilities to glue JavaScript and the DOM implementation together.
 
+use dom::bindings::codegen::InterfaceObjectMap;
 use dom::bindings::codegen::PrototypeList;
 use dom::bindings::codegen::PrototypeList::{MAX_PROTO_CHAIN_LENGTH, PROTO_OR_IFACE_LENGTH};
 use dom::bindings::conversions::{DOM_OBJECT_SLOT, is_dom_class};
@@ -18,17 +19,18 @@ use js;
 use js::error::throw_type_error;
 use js::glue::{CallJitGetterOp, CallJitMethodOp, CallJitSetterOp, IsWrapper};
 use js::glue::{GetCrossCompartmentWrapper, WrapperNew};
-use js::glue::{RUST_FUNCTION_VALUE_TO_JITINFO, RUST_JSID_IS_INT};
-use js::glue::{RUST_JSID_TO_INT, UnwrapObject};
+use js::glue::{RUST_FUNCTION_VALUE_TO_JITINFO, RUST_JSID_IS_INT, RUST_JSID_IS_STRING};
+use js::glue::{RUST_JSID_TO_INT, RUST_JSID_TO_STRING, UnwrapObject};
 use js::jsapi::{CallArgs, CompartmentOptions, DOMCallbacks, GetGlobalForObjectCrossCompartment};
 use js::jsapi::{HandleId, HandleObject, HandleValue, Heap, JSAutoCompartment, JSClass, JSContext};
 use js::jsapi::{JSJitInfo, JSObject, JSTraceOp, JSTracer, JSVersion, JSWrapObjectCallbacks};
-use js::jsapi::{JS_DeletePropertyById1, JS_FireOnNewGlobalObject};
-use js::jsapi::{JS_ForwardGetPropertyTo, JS_GetClass, JS_GetProperty, JS_GetPrototype};
-use js::jsapi::{JS_GetReservedSlot, JS_HasProperty, JS_HasPropertyById, JS_InitStandardClasses};
-use js::jsapi::{JS_IsExceptionPending, JS_NewGlobalObject, JS_ObjectToOuterObject, JS_SetProperty};
-use js::jsapi::{JS_SetReservedSlot, MutableHandleValue, ObjectOpResult, OnNewGlobalHookOption};
-use js::jsapi::{RootedObject};
+use js::jsapi::{JS_DeletePropertyById1, JS_EnumerateStandardClasses, JS_FireOnNewGlobalObject};
+use js::jsapi::{JS_ForwardGetPropertyTo, JS_GetClass, JS_GetLatin1StringCharsAndLength};
+use js::jsapi::{JS_GetProperty, JS_GetPrototype, JS_GetReservedSlot, JS_HasProperty};
+use js::jsapi::{JS_HasPropertyById, JS_IsExceptionPending, JS_IsGlobalObject, JS_NewGlobalObject};
+use js::jsapi::{JS_ObjectToOuterObject, JS_ResolveStandardClass, JS_SetProperty};
+use js::jsapi::{JS_SetReservedSlot, JS_StringHasLatin1Chars, MutableHandleValue, ObjectOpResult};
+use js::jsapi::{OnNewGlobalHookOption, RootedObject};
 use js::jsval::{JSVal};
 use js::jsval::{PrivateValue, UndefinedValue};
 use js::rust::{GCMethods, ToString};
@@ -38,6 +40,7 @@ use std::default::Default;
 use std::ffi::CString;
 use std::os::raw::c_void;
 use std::ptr;
+use std::slice;
 use util::non_geckolib::jsstring_to_str;
 
 /// Proxy handler for a WindowProxy.
@@ -334,7 +337,6 @@ pub fn create_dom_global(cx: *mut JSContext,
                            PrivateValue(Box::into_raw(proto_array) as *const libc::c_void));
 
         let _ac = JSAutoCompartment::new(cx, obj.ptr);
-        JS_InitStandardClasses(cx, obj.handle());
         JS_FireOnNewGlobalObject(cx, obj.handle());
         obj.ptr
     }
@@ -366,6 +368,56 @@ pub unsafe fn trace_global(tracer: *mut JSTracer, obj: *mut JSObject) {
     }
 }
 
+/// Enumerate lazy properties of a global object.
+pub unsafe extern "C" fn enumerate_global(cx: *mut JSContext, obj: HandleObject) -> bool {
+    assert!(JS_IsGlobalObject(obj.get()));
+    if !JS_EnumerateStandardClasses(cx, obj) {
+        return false;
+    }
+    for init_fun in InterfaceObjectMap::MAP.values() {
+        init_fun(cx, obj);
+    }
+    true
+}
+
+/// Resolve a lazy global property, for interface objects and named constructors.
+pub unsafe extern "C" fn resolve_global(
+        cx: *mut JSContext,
+        obj: HandleObject,
+        id: HandleId,
+        rval: *mut bool)
+        -> bool {
+    assert!(JS_IsGlobalObject(obj.get()));
+    if !JS_ResolveStandardClass(cx, obj, id, rval) {
+        return false;
+    }
+    if *rval {
+        return true;
+    }
+    if !RUST_JSID_IS_STRING(id) {
+        *rval = false;
+        return true;
+    }
+
+    let string = RUST_JSID_TO_STRING(id);
+    if !JS_StringHasLatin1Chars(string) {
+        *rval = false;
+        return true;
+    }
+    let mut length = 0;
+    let ptr = JS_GetLatin1StringCharsAndLength(cx, ptr::null(), string, &mut length);
+    assert!(!ptr.is_null());
+    let bytes = slice::from_raw_parts(ptr, length as usize);
+
+    if let Some(init_fun) = InterfaceObjectMap::MAP.get(bytes) {
+        init_fun(cx, obj);
+        *rval = true;
+    } else {
+        *rval = false;
+    }
+    true
+}
+
 unsafe extern "C" fn wrap(cx: *mut JSContext,
                           _existing: HandleObject,
                           obj: HandleObject)
diff --git a/components/script/lib.rs b/components/script/lib.rs
index dfd11938075..93ba1dba8a4 100644
--- a/components/script/lib.rs
+++ b/components/script/lib.rs
@@ -26,6 +26,7 @@
 #![doc = "The script crate contains all matters DOM."]
 
 #![plugin(heapsize_plugin)]
+#![plugin(phf_macros)]
 #![plugin(plugins)]
 
 extern crate angle;
@@ -55,6 +56,7 @@ extern crate msg;
 extern crate net_traits;
 extern crate num;
 extern crate offscreen_gl_context;
+extern crate phf;
 #[macro_use]
 extern crate profile_traits;
 extern crate rand;
diff --git a/components/servo/Cargo.lock b/components/servo/Cargo.lock
index 64acb9dc4d8..23a93b6e0f4 100644
--- a/components/servo/Cargo.lock
+++ b/components/servo/Cargo.lock
@@ -849,8 +849,8 @@ dependencies = [
  "heapsize_plugin 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.3.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "mac 0.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "phf 0.7.12 (registry+https://github.com/rust-lang/crates.io-index)",
- "phf_codegen 0.7.12 (registry+https://github.com/rust-lang/crates.io-index)",
+ "phf 0.7.13 (registry+https://github.com/rust-lang/crates.io-index)",
+ "phf_codegen 0.7.13 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc-serialize 0.3.16 (registry+https://github.com/rust-lang/crates.io-index)",
  "string_cache 0.2.10 (registry+https://github.com/rust-lang/crates.io-index)",
  "tendril 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1404,33 +1404,42 @@ dependencies = [
 
 [[package]]
 name = "phf"
-version = "0.7.12"
+version = "0.7.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "phf_shared 0.7.12 (registry+https://github.com/rust-lang/crates.io-index)",
+ "phf_shared 0.7.13 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "phf_codegen"
-version = "0.7.12"
+version = "0.7.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "phf_generator 0.7.12 (registry+https://github.com/rust-lang/crates.io-index)",
- "phf_shared 0.7.12 (registry+https://github.com/rust-lang/crates.io-index)",
+ "phf_generator 0.7.13 (registry+https://github.com/rust-lang/crates.io-index)",
+ "phf_shared 0.7.13 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "phf_generator"
-version = "0.7.12"
+version = "0.7.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "phf_shared 0.7.12 (registry+https://github.com/rust-lang/crates.io-index)",
+ "phf_shared 0.7.13 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand 0.3.12 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "phf_macros"
+version = "0.7.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "phf_generator 0.7.13 (registry+https://github.com/rust-lang/crates.io-index)",
+ "phf_shared 0.7.13 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "phf_shared"
-version = "0.7.12"
+version = "0.7.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
@@ -1622,6 +1631,8 @@ dependencies = [
  "net_traits 0.0.1",
  "num 0.1.28 (registry+https://github.com/rust-lang/crates.io-index)",
  "offscreen_gl_context 0.1.0 (git+https://github.com/ecoal95/rust-offscreen-rendering-context)",
+ "phf 0.7.13 (registry+https://github.com/rust-lang/crates.io-index)",
+ "phf_macros 0.7.13 (registry+https://github.com/rust-lang/crates.io-index)",
  "plugins 0.0.1",
  "profile_traits 0.0.1",
  "rand 0.3.12 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1870,8 +1881,8 @@ dependencies = [
  "heapsize 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "heapsize_plugin 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 0.1.15 (registry+https://github.com/rust-lang/crates.io-index)",
- "phf_generator 0.7.12 (registry+https://github.com/rust-lang/crates.io-index)",
- "phf_shared 0.7.12 (registry+https://github.com/rust-lang/crates.io-index)",
+ "phf_generator 0.7.13 (registry+https://github.com/rust-lang/crates.io-index)",
+ "phf_shared 0.7.13 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 0.6.15 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -2318,8 +2329,8 @@ source = "git+https://github.com/Ygg01/xml5ever#6c7017063dc1cfd64f08b7701a689e74
 dependencies = [
  "log 0.3.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "mac 0.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "phf 0.7.12 (registry+https://github.com/rust-lang/crates.io-index)",
- "phf_codegen 0.7.12 (registry+https://github.com/rust-lang/crates.io-index)",
+ "phf 0.7.13 (registry+https://github.com/rust-lang/crates.io-index)",
+ "phf_codegen 0.7.13 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc-serialize 0.3.16 (registry+https://github.com/rust-lang/crates.io-index)",
  "string_cache 0.2.10 (registry+https://github.com/rust-lang/crates.io-index)",
  "tendril 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
diff --git a/ports/cef/Cargo.lock b/ports/cef/Cargo.lock
index 13105ecccd3..d0ec8af8c64 100644
--- a/ports/cef/Cargo.lock
+++ b/ports/cef/Cargo.lock
@@ -779,8 +779,8 @@ dependencies = [
  "heapsize_plugin 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.3.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "mac 0.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "phf 0.7.12 (registry+https://github.com/rust-lang/crates.io-index)",
- "phf_codegen 0.7.12 (registry+https://github.com/rust-lang/crates.io-index)",
+ "phf 0.7.13 (registry+https://github.com/rust-lang/crates.io-index)",
+ "phf_codegen 0.7.13 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc-serialize 0.3.16 (registry+https://github.com/rust-lang/crates.io-index)",
  "string_cache 0.2.10 (registry+https://github.com/rust-lang/crates.io-index)",
  "tendril 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1308,33 +1308,42 @@ dependencies = [
 
 [[package]]
 name = "phf"
-version = "0.7.12"
+version = "0.7.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "phf_shared 0.7.12 (registry+https://github.com/rust-lang/crates.io-index)",
+ "phf_shared 0.7.13 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "phf_codegen"
-version = "0.7.12"
+version = "0.7.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "phf_generator 0.7.12 (registry+https://github.com/rust-lang/crates.io-index)",
- "phf_shared 0.7.12 (registry+https://github.com/rust-lang/crates.io-index)",
+ "phf_generator 0.7.13 (registry+https://github.com/rust-lang/crates.io-index)",
+ "phf_shared 0.7.13 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "phf_generator"
-version = "0.7.12"
+version = "0.7.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "phf_shared 0.7.12 (registry+https://github.com/rust-lang/crates.io-index)",
+ "phf_shared 0.7.13 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand 0.3.12 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "phf_macros"
+version = "0.7.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "phf_generator 0.7.13 (registry+https://github.com/rust-lang/crates.io-index)",
+ "phf_shared 0.7.13 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "phf_shared"
-version = "0.7.12"
+version = "0.7.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
@@ -1508,6 +1517,8 @@ dependencies = [
  "net_traits 0.0.1",
  "num 0.1.28 (registry+https://github.com/rust-lang/crates.io-index)",
  "offscreen_gl_context 0.1.0 (git+https://github.com/ecoal95/rust-offscreen-rendering-context)",
+ "phf 0.7.13 (registry+https://github.com/rust-lang/crates.io-index)",
+ "phf_macros 0.7.13 (registry+https://github.com/rust-lang/crates.io-index)",
  "plugins 0.0.1",
  "profile_traits 0.0.1",
  "rand 0.3.12 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1784,8 +1795,8 @@ dependencies = [
  "heapsize 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "heapsize_plugin 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 0.1.15 (registry+https://github.com/rust-lang/crates.io-index)",
- "phf_generator 0.7.12 (registry+https://github.com/rust-lang/crates.io-index)",
- "phf_shared 0.7.12 (registry+https://github.com/rust-lang/crates.io-index)",
+ "phf_generator 0.7.13 (registry+https://github.com/rust-lang/crates.io-index)",
+ "phf_shared 0.7.13 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 0.6.15 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -2204,8 +2215,8 @@ source = "git+https://github.com/Ygg01/xml5ever#6c7017063dc1cfd64f08b7701a689e74
 dependencies = [
  "log 0.3.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "mac 0.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "phf 0.7.12 (registry+https://github.com/rust-lang/crates.io-index)",
- "phf_codegen 0.7.12 (registry+https://github.com/rust-lang/crates.io-index)",
+ "phf 0.7.13 (registry+https://github.com/rust-lang/crates.io-index)",
+ "phf_codegen 0.7.13 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc-serialize 0.3.16 (registry+https://github.com/rust-lang/crates.io-index)",
  "string_cache 0.2.10 (registry+https://github.com/rust-lang/crates.io-index)",
  "tendril 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
diff --git a/ports/geckolib/Cargo.lock b/ports/geckolib/Cargo.lock
index ccb5729e639..a1f5a87933c 100644
--- a/ports/geckolib/Cargo.lock
+++ b/ports/geckolib/Cargo.lock
@@ -277,16 +277,16 @@ dependencies = [
 
 [[package]]
 name = "phf_generator"
-version = "0.7.12"
+version = "0.7.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "phf_shared 0.7.12 (registry+https://github.com/rust-lang/crates.io-index)",
+ "phf_shared 0.7.13 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand 0.3.12 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "phf_shared"
-version = "0.7.12"
+version = "0.7.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
@@ -414,8 +414,8 @@ dependencies = [
  "heapsize 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "heapsize_plugin 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 0.1.15 (registry+https://github.com/rust-lang/crates.io-index)",
- "phf_generator 0.7.12 (registry+https://github.com/rust-lang/crates.io-index)",
- "phf_shared 0.7.12 (registry+https://github.com/rust-lang/crates.io-index)",
+ "phf_generator 0.7.13 (registry+https://github.com/rust-lang/crates.io-index)",
+ "phf_shared 0.7.13 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 0.6.15 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
diff --git a/ports/gonk/Cargo.lock b/ports/gonk/Cargo.lock
index e6bd009f27d..f8dffe9ed2b 100644
--- a/ports/gonk/Cargo.lock
+++ b/ports/gonk/Cargo.lock
@@ -760,8 +760,8 @@ dependencies = [
  "heapsize_plugin 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.3.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "mac 0.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "phf 0.7.12 (registry+https://github.com/rust-lang/crates.io-index)",
- "phf_codegen 0.7.12 (registry+https://github.com/rust-lang/crates.io-index)",
+ "phf 0.7.13 (registry+https://github.com/rust-lang/crates.io-index)",
+ "phf_codegen 0.7.13 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc-serialize 0.3.16 (registry+https://github.com/rust-lang/crates.io-index)",
  "string_cache 0.2.10 (registry+https://github.com/rust-lang/crates.io-index)",
  "tendril 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1289,33 +1289,42 @@ dependencies = [
 
 [[package]]
 name = "phf"
-version = "0.7.12"
+version = "0.7.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "phf_shared 0.7.12 (registry+https://github.com/rust-lang/crates.io-index)",
+ "phf_shared 0.7.13 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "phf_codegen"
-version = "0.7.12"
+version = "0.7.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "phf_generator 0.7.12 (registry+https://github.com/rust-lang/crates.io-index)",
- "phf_shared 0.7.12 (registry+https://github.com/rust-lang/crates.io-index)",
+ "phf_generator 0.7.13 (registry+https://github.com/rust-lang/crates.io-index)",
+ "phf_shared 0.7.13 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "phf_generator"
-version = "0.7.12"
+version = "0.7.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "phf_shared 0.7.12 (registry+https://github.com/rust-lang/crates.io-index)",
+ "phf_shared 0.7.13 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand 0.3.12 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "phf_macros"
+version = "0.7.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "phf_generator 0.7.13 (registry+https://github.com/rust-lang/crates.io-index)",
+ "phf_shared 0.7.13 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "phf_shared"
-version = "0.7.12"
+version = "0.7.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
@@ -1489,6 +1498,8 @@ dependencies = [
  "net_traits 0.0.1",
  "num 0.1.28 (registry+https://github.com/rust-lang/crates.io-index)",
  "offscreen_gl_context 0.1.0 (git+https://github.com/ecoal95/rust-offscreen-rendering-context)",
+ "phf 0.7.13 (registry+https://github.com/rust-lang/crates.io-index)",
+ "phf_macros 0.7.13 (registry+https://github.com/rust-lang/crates.io-index)",
  "plugins 0.0.1",
  "profile_traits 0.0.1",
  "rand 0.3.12 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1763,8 +1774,8 @@ dependencies = [
  "heapsize 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "heapsize_plugin 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 0.1.15 (registry+https://github.com/rust-lang/crates.io-index)",
- "phf_generator 0.7.12 (registry+https://github.com/rust-lang/crates.io-index)",
- "phf_shared 0.7.12 (registry+https://github.com/rust-lang/crates.io-index)",
+ "phf_generator 0.7.13 (registry+https://github.com/rust-lang/crates.io-index)",
+ "phf_shared 0.7.13 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 0.6.15 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -2152,8 +2163,8 @@ source = "git+https://github.com/Ygg01/xml5ever#6c7017063dc1cfd64f08b7701a689e74
 dependencies = [
  "log 0.3.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "mac 0.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "phf 0.7.12 (registry+https://github.com/rust-lang/crates.io-index)",
- "phf_codegen 0.7.12 (registry+https://github.com/rust-lang/crates.io-index)",
+ "phf 0.7.13 (registry+https://github.com/rust-lang/crates.io-index)",
+ "phf_codegen 0.7.13 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc-serialize 0.3.16 (registry+https://github.com/rust-lang/crates.io-index)",
  "string_cache 0.2.10 (registry+https://github.com/rust-lang/crates.io-index)",
  "tendril 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
diff --git a/tests/wpt/metadata/MANIFEST.json b/tests/wpt/metadata/MANIFEST.json
index c3e65a34e55..6ef0d6a1b71 100644
--- a/tests/wpt/metadata/MANIFEST.json
+++ b/tests/wpt/metadata/MANIFEST.json
@@ -34494,7 +34494,16 @@
   },
   "local_changes": {
     "deleted": [],
-    "items": {},
+    "items": {
+      "testharness": {
+        "WebIDL/ecmascript-binding/interface-object.html": [
+          {
+            "path": "WebIDL/ecmascript-binding/interface-object.html",
+            "url": "/WebIDL/ecmascript-binding/interface-object.html"
+          }
+        ]
+      }
+    },
     "reftest_nodes": {}
   },
   "reftest_nodes": {
diff --git a/tests/wpt/web-platform-tests/WebIDL/ecmascript-binding/interface-object.html b/tests/wpt/web-platform-tests/WebIDL/ecmascript-binding/interface-object.html
new file mode 100644
index 00000000000..132c61ddaed
--- /dev/null
+++ b/tests/wpt/web-platform-tests/WebIDL/ecmascript-binding/interface-object.html
@@ -0,0 +1,28 @@
+<!doctype html>
+<meta charset="utf-8">
+<title>Interface objects</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+test(function () {
+    assert_equals(typeof window.Blob, "function")
+    delete window.Blob;
+    assert_equals(window.Blob, undefined);
+}, "An interface object deleted after it has been accessed is undefined");
+
+test(function () {
+    delete window.File;
+    assert_equals(window.File, undefined);
+}, "An interface object deleted before it has been defined is undefined");
+
+test(function () {
+    delete window.ImageData;
+    assert_equals(Object.getOwnPropertyDescriptor(window, "ImageData"), undefined);
+    delete window.ImageData;
+    assert_equals(Object.getOwnPropertyDescriptor(window, "ImageData"), undefined);
+}, "Interface objects deleted multiple times stay deleted");
+
+test(function () {
+    assert_equals(window["abc\udc88"], undefined);
+}, "Fancy property names don't break the resolve hook on Window");
+</script>