--- a/dom/base/Makefile.in
+++ b/dom/base/Makefile.in
@@ -79,16 +79,17 @@ EXPORTS = \
   $(NULL)
 
 EXPORTS_NAMESPACES = mozilla/dom
 EXPORTS_mozilla/dom = \
   DOMError.h \
   DOMRequest.h \
   StructuredCloneTags.h \
   ScreenOrientation.h \
+  URL.h \
   $(NULL)
 
 CPPSRCS =			\
 	nsBarProps.cpp          \
 	nsDOMException.cpp 	\
 	nsDOMWindowUtils.cpp 	\
 	nsJSEnvironment.cpp	\
 	nsJSTimeoutHandler.cpp	\
@@ -110,16 +111,17 @@ CPPSRCS =			\
 	nsContentPermissionHelper.cpp \
 	nsStructuredCloneContainer.cpp \
 	nsDOMNavigationTiming.cpp \
 	nsPerformance.cpp	\
 	nsWindowMemoryReporter.cpp \
 	DOMError.cpp \
 	DOMRequest.cpp \
 	Navigator.cpp \
+	URL.cpp \
 	$(NULL)
 
 include $(topsrcdir)/dom/dom-config.mk
 
 ifdef MOZ_JSDEBUGGER
 DEFINES += -DMOZ_JSDEBUGGER
 endif
 

new file mode 100644
--- /dev/null
+++ b/dom/base/URL.cpp
@@ -0,0 +1,76 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "URL.h"
+
+#include "nsGlobalWindow.h"
+#include "nsIDOMFile.h"
+#include "nsIDocument.h"
+#include "nsIPrincipal.h"
+#include "nsContentUtils.h"
+#include "nsBlobProtocolHandler.h"
+
+namespace mozilla {
+namespace dom {
+
+void
+URL::CreateObjectURL(nsISupports* aGlobal, nsIDOMBlob* aBlob,
+                     const objectURLOptions& aOptions,
+                     nsAString& aResult,
+                     ErrorResult& aError)
+{
+  nsCOMPtr<nsPIDOMWindow> w = do_QueryInterface(aGlobal);
+  nsGlobalWindow* window = static_cast<nsGlobalWindow*>(w.get());
+  NS_PRECONDITION(!window || window->IsInnerWindow(),
+                  "Should be inner window");
+
+  if (!window || !window->GetExtantDoc()) {
+    aError.Throw(NS_ERROR_INVALID_POINTER);
+    return;
+  }
+
+  nsIDocument* doc = window->GetExtantDoc();
+
+  nsresult rv = aBlob->GetInternalUrl(doc->NodePrincipal(), aResult);
+  if (NS_FAILED(rv)) {
+    aError.Throw(rv);
+    return;
+  }
+
+  doc->RegisterFileDataUri(NS_LossyConvertUTF16toASCII(aResult));
+}
+
+void
+URL::RevokeObjectURL(nsISupports* aGlobal, const nsAString& aURL)
+{
+  nsCOMPtr<nsPIDOMWindow> w = do_QueryInterface(aGlobal);
+  nsGlobalWindow* window = static_cast<nsGlobalWindow*>(w.get());
+  NS_PRECONDITION(!window || window->IsInnerWindow(),
+                  "Should be inner window");
+  if (!window)
+    return;
+
+  NS_LossyConvertUTF16toASCII asciiurl(aURL);
+
+  nsIPrincipal* winPrincipal = window->GetPrincipal();
+  if (!winPrincipal) {
+    return;
+  }
+
+  nsIPrincipal* principal =
+    nsBlobProtocolHandler::GetFileDataEntryPrincipal(asciiurl);
+  bool subsumes;
+  if (principal && winPrincipal &&
+      NS_SUCCEEDED(winPrincipal->Subsumes(principal, &subsumes)) &&
+      subsumes) {
+    if (window->GetExtantDoc()) {
+      window->GetExtantDoc()->UnregisterFileDataUri(asciiurl);
+    }
+    nsBlobProtocolHandler::RemoveFileDataEntry(asciiurl);
+  }
+}
+
+}
+}

new file mode 100644
--- /dev/null
+++ b/dom/base/URL.h
@@ -0,0 +1,30 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+#ifndef URL_h___
+#define URL_h___
+
+#include "nscore.h"
+#include "mozilla/dom/URLBinding.h"
+
+class nsIDOMBlob;
+
+namespace mozilla {
+namespace dom {
+
+class URL MOZ_FINAL
+{
+public:
+  // WebIDL methods
+  static void CreateObjectURL(nsISupports* aGlobal, nsIDOMBlob* aBlob,
+                              const objectURLOptions& aOptions,
+                              nsAString& aResult,
+                              ErrorResult& aError);
+  static void RevokeObjectURL(nsISupports* aGlobal, const nsAString& aURL);
+};
+
+}
+}
+
+#endif /* URL_h___ */

--- a/dom/base/nsDOMClassInfo.cpp
+++ b/dom/base/nsDOMClassInfo.cpp
@@ -1429,18 +1429,16 @@ static nsDOMClassInfoData sClassInfoData
   NS_DEFINE_CLASSINFO_DATA(File, nsDOMGenericSH,
                            DOM_DEFAULT_SCRIPTABLE_FLAGS)
   NS_DEFINE_CLASSINFO_DATA(FileReader, nsEventTargetSH,
                            EVENTTARGET_SCRIPTABLE_FLAGS)
   NS_DEFINE_CLASSINFO_DATA(ArchiveReader, nsDOMGenericSH,
                            DOM_DEFAULT_SCRIPTABLE_FLAGS)
   NS_DEFINE_CLASSINFO_DATA(ArchiveRequest, nsDOMGenericSH,
                            DOM_DEFAULT_SCRIPTABLE_FLAGS)
-  NS_DEFINE_CLASSINFO_DATA(MozURLProperty, nsDOMGenericSH,
-                           DOM_DEFAULT_SCRIPTABLE_FLAGS)
 
   NS_DEFINE_CLASSINFO_DATA(ModalContentWindow, nsWindowSH,
                            DEFAULT_SCRIPTABLE_FLAGS |
                            WINDOW_SCRIPTABLE_FLAGS)
 
   NS_DEFINE_CLASSINFO_DATA(DataContainerEvent, nsDOMGenericSH,
                            DOM_DEFAULT_SCRIPTABLE_FLAGS)
 
@@ -4003,20 +4001,16 @@ nsDOMClassInfo::Init()
     DOM_CLASSINFO_MAP_ENTRY(nsIDOMArchiveReader)
   DOM_CLASSINFO_MAP_END
 
   DOM_CLASSINFO_MAP_BEGIN(ArchiveRequest, nsIDOMArchiveRequest)
     DOM_CLASSINFO_MAP_ENTRY(nsIDOMArchiveRequest)
     DOM_CLASSINFO_MAP_ENTRY(nsIDOMDOMRequest)
   DOM_CLASSINFO_MAP_END
 
-  DOM_CLASSINFO_MAP_BEGIN(MozURLProperty, nsIDOMMozURLProperty)
-    DOM_CLASSINFO_MAP_ENTRY(nsIDOMMozURLProperty)
-  DOM_CLASSINFO_MAP_END
-
   DOM_CLASSINFO_MAP_BEGIN_NO_CLASS_IF(ModalContentWindow, nsIDOMWindow)
     DOM_CLASSINFO_WINDOW_MAP_ENTRIES(nsGlobalWindow::HasIndexedDBSupport())
     DOM_CLASSINFO_MAP_ENTRY(nsIDOMModalContentWindow)
   DOM_CLASSINFO_MAP_END
 
   DOM_CLASSINFO_MAP_BEGIN(DataContainerEvent, nsIDOMDataContainerEvent)
     DOM_CLASSINFO_MAP_ENTRY(nsIDOMDataContainerEvent)
     DOM_CLASSINFO_EVENT_MAP_ENTRIES

--- a/dom/base/nsDOMClassInfoClasses.h
+++ b/dom/base/nsDOMClassInfoClasses.h
@@ -361,17 +361,16 @@ DOMCI_CLASS(CommandEvent)
 DOMCI_CLASS(OfflineResourceList)
 
 DOMCI_CLASS(FileList)
 DOMCI_CLASS(Blob)
 DOMCI_CLASS(File)
 DOMCI_CLASS(FileReader)
 DOMCI_CLASS(ArchiveReader)
 DOMCI_CLASS(ArchiveRequest)
-DOMCI_CLASS(MozURLProperty)
 
 // DOM modal content window class, almost identical to Window
 DOMCI_CLASS(ModalContentWindow)
 
 // Data Events
 DOMCI_CLASS(DataContainerEvent)
 
 // event used for cross-domain message-passing and for server-sent events in

--- a/dom/base/nsGlobalWindow.cpp
+++ b/dom/base/nsGlobalWindow.cpp
@@ -143,17 +143,16 @@
 #include "nsIScriptError.h"
 #include "nsIConsoleService.h"
 #include "nsIControllers.h"
 #include "nsIControllerContext.h"
 #include "nsGlobalWindowCommands.h"
 #include "nsAutoPtr.h"
 #include "nsContentUtils.h"
 #include "nsCSSProps.h"
-#include "nsBlobProtocolHandler.h"
 #include "nsIDOMFile.h"
 #include "nsIDOMFileList.h"
 #include "nsIURIFixup.h"
 #include "nsCDefaultURIFixup.h"
 #include "nsEventDispatcher.h"
 #include "nsIObserverService.h"
 #include "nsIXULAppInfo.h"
 #include "nsNetUtil.h"
@@ -418,95 +417,16 @@ static const char kCryptoContractID[] = 
 static const char kPkcs11ContractID[] = NS_PKCS11_CONTRACTID;
 #endif
 static const char sPopStatePrefStr[] = "browser.history.allowPopState";
 
 #define NETWORK_UPLOAD_EVENT_NAME     NS_LITERAL_STRING("moznetworkupload")
 #define NETWORK_DOWNLOAD_EVENT_NAME   NS_LITERAL_STRING("moznetworkdownload")
 
 /**
- * An object implementing the window.URL property.
- */
-class nsDOMMozURLProperty MOZ_FINAL : public nsIDOMMozURLProperty
-{
-public:
-  nsDOMMozURLProperty(nsGlobalWindow* aWindow)
-    : mWindow(aWindow)
-  {
-  }
-
-  NS_DECL_ISUPPORTS
-  NS_DECL_NSIDOMMOZURLPROPERTY
-
-  void ClearWindowReference() {
-    mWindow = nullptr;
-  }
-private:
-  nsGlobalWindow* mWindow;
-};
-
-DOMCI_DATA(MozURLProperty, nsDOMMozURLProperty)
-NS_IMPL_ADDREF(nsDOMMozURLProperty)
-NS_IMPL_RELEASE(nsDOMMozURLProperty)
-NS_INTERFACE_MAP_BEGIN(nsDOMMozURLProperty)
-    NS_INTERFACE_MAP_ENTRY(nsIDOMMozURLProperty)
-    NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIDOMMozURLProperty)
-    NS_DOM_INTERFACE_MAP_ENTRY_CLASSINFO(MozURLProperty)
-NS_INTERFACE_MAP_END
-
-NS_IMETHODIMP
-nsDOMMozURLProperty::CreateObjectURL(nsIDOMBlob* aBlob, nsAString& aURL)
-{
-  NS_PRECONDITION(!mWindow || mWindow->IsInnerWindow(),
-                  "Should be inner window");
-
-  NS_ENSURE_STATE(mWindow && mWindow->mDoc);
-  NS_ENSURE_ARG_POINTER(aBlob);
-
-  nsIDocument* doc = mWindow->mDoc;
-
-  nsresult rv = aBlob->GetInternalUrl(doc->NodePrincipal(), aURL);
-  NS_ENSURE_SUCCESS(rv, rv);
-
-  doc->RegisterFileDataUri(NS_LossyConvertUTF16toASCII(aURL));
-
-  return NS_OK;
-}
-
-NS_IMETHODIMP
-nsDOMMozURLProperty::RevokeObjectURL(const nsAString& aURL)
-{
-  NS_PRECONDITION(!mWindow || mWindow->IsInnerWindow(),
-                  "Should be inner window");
-
-  NS_ENSURE_STATE(mWindow);
-
-  NS_LossyConvertUTF16toASCII asciiurl(aURL);
-
-  nsIPrincipal* winPrincipal = mWindow->GetPrincipal();
-  if (!winPrincipal) {
-    return NS_OK;
-  }
-
-  nsIPrincipal* principal =
-    nsBlobProtocolHandler::GetFileDataEntryPrincipal(asciiurl);
-  bool subsumes;
-  if (principal && winPrincipal &&
-      NS_SUCCEEDED(winPrincipal->Subsumes(principal, &subsumes)) &&
-      subsumes) {
-    if (mWindow->mDoc) {
-      mWindow->mDoc->UnregisterFileDataUri(asciiurl);
-    }
-    nsBlobProtocolHandler::RemoveFileDataEntry(asciiurl);
-  }
-
-  return NS_OK;
-}
-
-/**
  * An indirect observer object that means we don't have to implement nsIObserver
  * on nsGlobalWindow, where any script could see it.
  */
 class nsGlobalWindowObserver MOZ_FINAL : public nsIObserver,
                                          public nsIInterfaceRequestor
 {
 public:
   nsGlobalWindowObserver(nsGlobalWindow* aWindow) : mWindow(aWindow) {}
@@ -923,20 +843,16 @@ nsGlobalWindow::~nsGlobalWindow()
   NS_ASSERTION(!mArguments, "mArguments wasn't cleaned up properly!");
 
   CleanUp(true);
 
 #ifdef DEBUG
   nsCycleCollector_DEBUG_wasFreed(static_cast<nsIScriptGlobalObject*>(this));
 #endif
 
-  if (mURLProperty) {
-    mURLProperty->ClearWindowReference();
-  }
-
   nsCOMPtr<nsIDeviceSensors> ac = do_GetService(NS_DEVICE_SENSORS_CONTRACTID);
   if (ac)
     ac->RemoveWindowAsListener(this);
 
   nsLayoutStatics::Release();
 }
 
 void
@@ -10765,30 +10681,16 @@ nsGlobalWindow::DisableDeviceSensor(uint
   }
 
   nsCOMPtr<nsIDeviceSensors> ac = do_GetService(NS_DEVICE_SENSORS_CONTRACTID);
   if (ac) {
     ac->RemoveWindowListener(aType, this);
   }
 }
 
-NS_IMETHODIMP
-nsGlobalWindow::GetURL(nsIDOMMozURLProperty** aURL)
-{
-  FORWARD_TO_INNER(GetURL, (aURL), NS_ERROR_UNEXPECTED);
-
-  if (!mURLProperty) {
-    mURLProperty = new nsDOMMozURLProperty(this);
-  }
-
-  NS_ADDREF(*aURL = mURLProperty);
-
-  return NS_OK;
-}
-
 void
 nsGlobalWindow::EnableTimeChangeNotifications()
 {
   nsSystemTimeChangeObserver::AddWindowListener(this);
 }
 
 void
 nsGlobalWindow::DisableTimeChangeNotifications()

--- a/dom/base/nsGlobalWindow.h
+++ b/dom/base/nsGlobalWindow.h
@@ -106,29 +106,29 @@ class nsPerformance;
 class nsIDocShellLoadInfo;
 class WindowStateHolder;
 class nsGlobalWindowObserver;
 class nsGlobalWindow;
 class PostMessageEvent;
 class nsRunnable;
 class nsDOMEventTargetHelper;
 class nsDOMOfflineResourceList;
-class nsDOMMozURLProperty;
 class nsDOMWindowUtils;
 class nsIIdleService;
 
 #ifdef MOZ_DISABLE_DOMCRYPTO
 class nsIDOMCrypto;
 #endif
 
 class nsWindowSizes;
 
 namespace mozilla {
 namespace dom {
 class Navigator;
+class URL;
 } // namespace dom
 } // namespace mozilla
 
 extern nsresult
 NS_CreateJSTimeoutHandler(nsGlobalWindow *aWindow,
                           bool *aIsInterval,
                           int32_t *aInterval,
                           nsIScriptTimeoutHandler **aRet);
@@ -277,18 +277,16 @@ class nsGlobalWindow : public nsPIDOMWin
                        public nsITouchEventReceiver,
                        public nsIInlineEventHandlers,
                        public nsIWindowCrypto
 #ifdef MOZ_B2G
                      , public nsIDOMWindowB2G
 #endif // MOZ_B2G
 {
 public:
-  friend class nsDOMMozURLProperty;
-
   typedef mozilla::TimeStamp TimeStamp;
   typedef mozilla::TimeDuration TimeDuration;
   typedef mozilla::dom::Navigator Navigator;
   typedef nsDataHashtable<nsUint64HashKey, nsGlobalWindow*> WindowByIdTable;
 
   // public methods
   nsPIDOMWindow* GetPrivateParent();
   // callback for close event
@@ -1123,18 +1121,16 @@ protected:
   // mDialogAbuseCount gets reset.
   bool                          mStopAbuseDialogs;
 
   // This flag gets set when dialogs should be permanently disabled for this
   // window (e.g. when we are closing the tab and therefore are guaranteed to be
   // destroying this window).
   bool                          mDialogsPermanentlyDisabled;
 
-  nsRefPtr<nsDOMMozURLProperty> mURLProperty;
-
   nsTHashtable<nsPtrHashKey<nsDOMEventTargetHelper> > mEventTargetObjects;
 
   nsTArray<uint32_t> mEnabledSensors;
 
   friend class nsDOMScriptableHelper;
   friend class nsDOMWindowUtils;
   friend class PostMessageEvent;
 

--- a/dom/base/nsPIDOMWindow.h
+++ b/dom/base/nsPIDOMWindow.h
@@ -43,18 +43,18 @@ class nsIDocument;
 class nsIScriptTimeoutHandler;
 struct nsTimeout;
 template <class> class nsScriptObjectHolder;
 class nsXBLPrototypeHandler;
 class nsIArray;
 class nsPIWindowRoot;
 
 #define NS_PIDOMWINDOW_IID \
-{ 0x54fd92bd, 0xda33, 0x4451, \
-  { 0x8f, 0xb5, 0x11, 0x20, 0x5c, 0x03, 0xce, 0xaa } }
+{ 0x7b18e421, 0x2179, 0x4e24, \
+  { 0x96, 0x58, 0x26, 0x75, 0xa4, 0x37, 0xf3, 0x8f } }
 
 class nsPIDOMWindow : public nsIDOMWindowInternal
 {
 public:
   NS_DECLARE_STATIC_IID_ACCESSOR(NS_PIDOMWINDOW_IID)
 
   virtual nsPIDOMWindow* GetPrivateRoot() = 0;
 

--- a/dom/bindings/Bindings.conf
+++ b/dom/bindings/Bindings.conf
@@ -360,16 +360,20 @@ DOMInterfaces = {
     'headerFile': 'DOMSVGTransformList.h',
     'resultNotAddRefed': [ 'getItem' ]
 },
 
 'TextEncoder': {
     'implicitJSContext': [ 'encode' ],
 },
 
+'URL' : {
+    'concrete': False,
+},
+
 'WebGLActiveInfo': {
    'nativeType': 'mozilla::WebGLActiveInfo',
    'headerFile': 'WebGLContext.h',
    'wrapperCache': False
 },
 
 'WebGLBuffer': {
    'nativeType': 'mozilla::WebGLBuffer',

--- a/dom/bindings/Codegen.py
+++ b/dom/bindings/Codegen.py
@@ -5631,60 +5631,63 @@ def stripTrailingWhitespace(text):
 
 class CGDescriptor(CGThing):
     def __init__(self, descriptor):
         CGThing.__init__(self)
 
         assert not descriptor.concrete or descriptor.interface.hasInterfacePrototypeObject()
 
         cgThings = []
-        if descriptor.interface.hasInterfacePrototypeObject():
-            # These are set to true if at least one non-static
-            # method/getter/setter exist on the interface.
-            (hasMethod, hasGetter, hasLenientGetter,
-             hasSetter, hasLenientSetter) = False, False, False, False, False
-            for m in descriptor.interface.members:
-                if (m.isMethod() and
-                    (not m.isIdentifierLess() or m == descriptor.operations['Stringifier'])):
-                    if m.isStatic():
-                        cgThings.append(CGStaticMethod(descriptor, m))
+        # These are set to true if at least one non-static
+        # method/getter/setter exist on the interface.
+        (hasMethod, hasGetter, hasLenientGetter,
+         hasSetter, hasLenientSetter) = False, False, False, False, False
+        for m in descriptor.interface.members:
+            if (m.isMethod() and
+                (not m.isIdentifierLess() or m == descriptor.operations['Stringifier'])):
+                if m.isStatic():
+                    assert descriptor.interface.hasInterfaceObject
+                    cgThings.append(CGStaticMethod(descriptor, m))
+                elif descriptor.interface.hasInterfacePrototypeObject():
+                    cgThings.append(CGSpecializedMethod(descriptor, m))
+                    cgThings.append(CGMemberJITInfo(descriptor, m))
+                    hasMethod = True
+            elif m.isAttr():
+                if m.isStatic():
+                    assert descriptor.interface.hasInterfaceObject
+                    cgThings.append(CGStaticGetter(descriptor, m))
+                elif descriptor.interface.hasInterfacePrototypeObject():
+                    cgThings.append(CGSpecializedGetter(descriptor, m))
+                    if m.hasLenientThis():
+                        hasLenientGetter = True
                     else:
-                        cgThings.append(CGSpecializedMethod(descriptor, m))
-                        cgThings.append(CGMemberJITInfo(descriptor, m))
-                        hasMethod = True
-                elif m.isAttr():
+                        hasGetter = True
+                if not m.readonly:
                     if m.isStatic():
-                        cgThings.append(CGStaticGetter(descriptor, m))
-                    else:
-                        cgThings.append(CGSpecializedGetter(descriptor, m))
+                        assert descriptor.interface.hasInterfaceObject
+                        cgThings.append(CGStaticSetter(descriptor, m))
+                    elif descriptor.interface.hasInterfacePrototypeObject():
+                        cgThings.append(CGSpecializedSetter(descriptor, m))
                         if m.hasLenientThis():
-                            hasLenientGetter = True
+                            hasLenientSetter = True
                         else:
-                            hasGetter = True
-                    if not m.readonly:
-                        if m.isStatic():
-                            cgThings.append(CGStaticSetter(descriptor, m))
-                        else:
-                            cgThings.append(CGSpecializedSetter(descriptor, m))
-                            if m.hasLenientThis():
-                                hasLenientSetter = True
-                            else:
-                                hasSetter = True
-                    elif m.getExtendedAttribute("PutForwards"):
-                        cgThings.append(CGSpecializedForwardingSetter(descriptor, m))
-                        hasSetter = True
-                    if not m.isStatic():
-                        cgThings.append(CGMemberJITInfo(descriptor, m))
-            if hasMethod: cgThings.append(CGGenericMethod(descriptor))
-            if hasGetter: cgThings.append(CGGenericGetter(descriptor))
-            if hasLenientGetter: cgThings.append(CGGenericGetter(descriptor,
-                                                                 lenientThis=True))
-            if hasSetter: cgThings.append(CGGenericSetter(descriptor))
-            if hasLenientSetter: cgThings.append(CGGenericSetter(descriptor,
-                                                                 lenientThis=True))
+                            hasSetter = True
+                elif m.getExtendedAttribute("PutForwards"):
+                    cgThings.append(CGSpecializedForwardingSetter(descriptor, m))
+                    hasSetter = True
+                if (not m.isStatic() and
+                    descriptor.interface.hasInterfacePrototypeObject()):
+                    cgThings.append(CGMemberJITInfo(descriptor, m))
+        if hasMethod: cgThings.append(CGGenericMethod(descriptor))
+        if hasGetter: cgThings.append(CGGenericGetter(descriptor))
+        if hasLenientGetter: cgThings.append(CGGenericGetter(descriptor,
+                                                             lenientThis=True))
+        if hasSetter: cgThings.append(CGGenericSetter(descriptor))
+        if hasLenientSetter: cgThings.append(CGGenericSetter(descriptor,
+                                                             lenientThis=True))
 
         if descriptor.concrete:
             if descriptor.nativeOwnership == 'owned' or descriptor.nativeOwnership == 'refcounted':
                 cgThings.append(CGDeferredFinalizePointers(descriptor))
                 cgThings.append(CGGetDeferredFinalizePointers(descriptor))
                 cgThings.append(CGDeferredFinalize(descriptor))
 
             if not descriptor.proxy:

--- a/dom/interfaces/base/nsIDOMWindow.idl
+++ b/dom/interfaces/base/nsIDOMWindow.idl
@@ -11,33 +11,26 @@ interface nsIDOMBlob;
 interface nsIDOMLocation;
 interface nsIDOMMediaQueryList;
 interface nsIDOMOfflineResourceList;
 interface nsIDOMStorage;
 interface nsIPrompt;
 interface nsISelection;
 interface nsIVariant;
 
-[scriptable, uuid(8fc58f56-f769-4368-a098-edd08550cf1a)]
-interface nsIDOMMozURLProperty : nsISupports
-{
-  DOMString createObjectURL(in nsIDOMBlob blob);
-  void revokeObjectURL(in DOMString URL);
-};
-
 /**
  * The nsIDOMWindow interface is the primary interface for a DOM
  * window object. It represents a single window object that may
  * contain child windows if the document in the window contains a
  * HTML frameset document or if the document contains iframe elements.
  *
  * @see <http://www.whatwg.org/html/#window>
  */
 
-[scriptable, uuid(1534ecd7-e298-420e-9063-e6c2d1243d49)]
+[scriptable, uuid(b9c71e0b-7f81-419a-8253-91f4c8893c4f)]
 interface nsIDOMWindow : nsISupports
 {
   // the current browsing context
   readonly attribute nsIDOMWindow                       window;
 
   /* [replaceable] self */
   readonly attribute nsIDOMWindow                       self;
 
@@ -457,21 +450,16 @@ interface nsIDOMWindow : nsISupports
   void mozCancelRequestAnimationFrame(in long aHandle);
 
   /**
    * The current animation start time in milliseconds since the epoch.
    */
   readonly attribute long long mozAnimationStartTime;
 
   /**
-   * @see <http://dev.w3.org/2006/webapi/FileAPI/#creating-revoking>
-   */
-  readonly attribute nsIDOMMozURLProperty URL;
-
-  /**
    * HTML5 event attributes that only apply to windows and <body>/<frameset>
    */
   [implicit_jscontext] attribute jsval onafterprint;
   [implicit_jscontext] attribute jsval onbeforeprint;
   [implicit_jscontext] attribute jsval onbeforeunload;
   [implicit_jscontext] attribute jsval onhashchange;
   [implicit_jscontext] attribute jsval onmessage;
   [implicit_jscontext] attribute jsval onoffline;
@@ -520,10 +508,10 @@ interface nsIWindowCrypto : nsISupports
   readonly attribute nsIDOMCrypto                       crypto;
   readonly attribute nsIDOMPkcs11                       pkcs11;
 };
 
 /**
  * Empty interface for compatibility with older versions.
  * @deprecated Use nsIDOMWindow instead
  */
-[scriptable, uuid(8da641ab-906a-456e-97f2-b77df4ca2d95)]
+[scriptable, uuid(a5cd0946-bac1-4606-9aaa-9e68dd0a3279)]
 interface nsIDOMWindowInternal : nsIDOMWindow {};

--- a/dom/tests/mochitest/general/test_interfaces.html
+++ b/dom/tests/mochitest/general/test_interfaces.html
@@ -337,17 +337,17 @@ var interfaceNamesInGlobalScope =
     "MozSmsManager",
     "MozSmsFilter",
     "SVGFETileElement",
     "MozMobileConnectionInfo",
     "CSSRule",
     "HTMLSelectElement",
     "MessageEvent",
     "SVGFEImageElement",
-    "MozURLProperty",
+    "URL",
     "DeviceStorage",
     "SVGFEOffsetElement",
     "DOMImplementation",
     "SVGFECompositeElement",
     "MediaList",
     "HTMLFrameElement",
     "NodeList",
     "SVGPathSegCurvetoQuadraticRel",

new file mode 100644
--- /dev/null
+++ b/dom/webidl/URL.webidl
@@ -0,0 +1,23 @@
+/* -*- Mode: IDL; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * The origins of this IDL file are
+ * http://dev.w3.org/2006/webapi/FileAPI/#creating-revoking
+ * http://dev.w3.org/2011/webrtc/editor/getusermedia.html#url
+ *
+ * Copyright © 2012 W3C® (MIT, ERCIM, Keio), All Rights Reserved. W3C
+ * liability, trademark and document use rules apply.
+ */
+
+interface URL {
+  [Throws]
+  static DOMString? createObjectURL(Blob blob, optional objectURLOptions options);
+  static void revokeObjectURL(DOMString url);
+};
+
+dictionary objectURLOptions
+{
+/* boolean autoRevoke = true; */ /* not supported yet */
+};

--- a/dom/webidl/WebIDL.mk
+++ b/dom/webidl/WebIDL.mk
@@ -47,16 +47,17 @@ webidl_files = \
   Screen.webidl \
   SVGLengthList.webidl \
   SVGNumberList.webidl \
   SVGPathSegList.webidl \
   SVGPointList.webidl \
   SVGTransformList.webidl \
   TextDecoder.webidl \
   TextEncoder.webidl \
+  URL.webidl \
   WebSocket.webidl \
   XMLHttpRequest.webidl \
   XMLHttpRequestEventTarget.webidl \
   XMLHttpRequestUpload.webidl \
   $(NULL)
 
 ifdef MOZ_WEBGL
 webidl_files += \