diff --git a/content/base/src/DocumentFragment.cpp b/content/base/src/DocumentFragment.cpp
index f3b81605725..01bca88a656 100644
--- a/content/base/src/DocumentFragment.cpp
+++ b/content/base/src/DocumentFragment.cpp
@@ -150,6 +150,7 @@ NS_INTERFACE_MAP_BEGIN(DocumentFragment)
   NS_INTERFACE_MAP_ENTRY(nsIDOMDocumentFragment)
   NS_INTERFACE_MAP_ENTRY(nsIDOMNode)
   NS_INTERFACE_MAP_ENTRY(nsIDOMEventTarget)
+  NS_INTERFACE_MAP_ENTRY(mozilla::dom::EventTarget)
   NS_INTERFACE_MAP_ENTRY_TEAROFF(nsISupportsWeakReference,
                                  new nsNodeSupportsWeakRefTearoff(this))
   NS_INTERFACE_MAP_ENTRY_TEAROFF(nsIDOMNodeSelector,
diff --git a/content/base/src/FragmentOrElement.cpp b/content/base/src/FragmentOrElement.cpp
index 672c0590e7a..5ad26614dfe 100644
--- a/content/base/src/FragmentOrElement.cpp
+++ b/content/base/src/FragmentOrElement.cpp
@@ -1664,6 +1664,7 @@ NS_INTERFACE_MAP_BEGIN(FragmentOrElement)
   NS_INTERFACE_MAP_ENTRY(nsIContent)
   NS_INTERFACE_MAP_ENTRY(nsINode)
   NS_INTERFACE_MAP_ENTRY(nsIDOMEventTarget)
+  NS_INTERFACE_MAP_ENTRY(mozilla::dom::EventTarget)
   NS_INTERFACE_MAP_ENTRY_TEAROFF(nsISupportsWeakReference,
                                  new nsNodeSupportsWeakRefTearoff(this))
   NS_INTERFACE_MAP_ENTRY_TEAROFF(nsIDOMNodeSelector,
diff --git a/content/base/src/nsDocument.cpp b/content/base/src/nsDocument.cpp
index 6d42aedb9b4..c8545876180 100644
--- a/content/base/src/nsDocument.cpp
+++ b/content/base/src/nsDocument.cpp
@@ -1480,6 +1480,7 @@ NS_INTERFACE_TABLE_HEAD(nsDocument)
     NS_INTERFACE_TABLE_ENTRY(nsDocument, nsIDOMDocumentXBL)
     NS_INTERFACE_TABLE_ENTRY(nsDocument, nsIScriptObjectPrincipal)
     NS_INTERFACE_TABLE_ENTRY(nsDocument, nsIDOMEventTarget)
+    NS_INTERFACE_TABLE_ENTRY(nsDocument, mozilla::dom::EventTarget)
     NS_INTERFACE_TABLE_ENTRY(nsDocument, nsISupportsWeakReference)
     NS_INTERFACE_TABLE_ENTRY(nsDocument, nsIRadioGroupContainer)
     NS_INTERFACE_TABLE_ENTRY(nsDocument, nsIMutationObserver)
diff --git a/content/base/src/nsGenericDOMDataNode.cpp b/content/base/src/nsGenericDOMDataNode.cpp
index d00de26d381..7a4a03bd650 100644
--- a/content/base/src/nsGenericDOMDataNode.cpp
+++ b/content/base/src/nsGenericDOMDataNode.cpp
@@ -100,6 +100,7 @@ NS_INTERFACE_MAP_BEGIN(nsGenericDOMDataNode)
   NS_INTERFACE_MAP_ENTRY(nsIContent)
   NS_INTERFACE_MAP_ENTRY(nsINode)
   NS_INTERFACE_MAP_ENTRY(nsIDOMEventTarget)
+  NS_INTERFACE_MAP_ENTRY(mozilla::dom::EventTarget)
   NS_INTERFACE_MAP_ENTRY_TEAROFF(nsISupportsWeakReference,
                                  new nsNodeSupportsWeakRefTearoff(this))
   NS_INTERFACE_MAP_ENTRY_TEAROFF(nsIDOMXPathNSResolver,
diff --git a/content/events/src/nsDOMEventTargetHelper.cpp b/content/events/src/nsDOMEventTargetHelper.cpp
index 0b12e197052..4e75b869e6c 100644
--- a/content/events/src/nsDOMEventTargetHelper.cpp
+++ b/content/events/src/nsDOMEventTargetHelper.cpp
@@ -66,6 +66,7 @@ NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(nsDOMEventTargetHelper)
   NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
   NS_INTERFACE_MAP_ENTRY(nsISupports)
   NS_INTERFACE_MAP_ENTRY(nsIDOMEventTarget)
+  NS_INTERFACE_MAP_ENTRY(mozilla::dom::EventTarget)
 NS_INTERFACE_MAP_END
 
 NS_IMPL_CYCLE_COLLECTING_ADDREF(nsDOMEventTargetHelper)
diff --git a/dom/base/nsGlobalWindow.cpp b/dom/base/nsGlobalWindow.cpp
index 8844bf7fb2c..bfbba6b5ede 100644
--- a/dom/base/nsGlobalWindow.cpp
+++ b/dom/base/nsGlobalWindow.cpp
@@ -1473,6 +1473,7 @@ NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(nsGlobalWindow)
   NS_INTERFACE_MAP_ENTRY(nsIScriptGlobalObject)
   NS_INTERFACE_MAP_ENTRY(nsIScriptObjectPrincipal)
   NS_INTERFACE_MAP_ENTRY(nsIDOMEventTarget)
+  NS_INTERFACE_MAP_ENTRY(mozilla::dom::EventTarget)
   NS_INTERFACE_MAP_ENTRY(nsPIDOMWindow)
   NS_INTERFACE_MAP_ENTRY(nsIDOMStorageIndexedDB)
   NS_INTERFACE_MAP_ENTRY(nsISupportsWeakReference)
diff --git a/dom/base/nsGlobalWindow.h b/dom/base/nsGlobalWindow.h
index 9f7ed3c62c8..40dc4f61494 100644
--- a/dom/base/nsGlobalWindow.h
+++ b/dom/base/nsGlobalWindow.h
@@ -67,6 +67,8 @@
 #include "nsIIdleObserver.h"
 #include "nsIDOMWakeLock.h"
 
+#include "mozilla/dom/EventTarget.h"
+
 // JS includes
 #include "jsapi.h"
 
@@ -253,15 +255,14 @@ struct IdleObserverHolder
 // belonging to the same outer window, but that's an unimportant
 // side effect of inheriting PRCList).
 
-class nsGlobalWindow : public nsPIDOMWindow,
+class nsGlobalWindow : public mozilla::dom::EventTarget,
+                       public nsPIDOMWindow,
                        public nsIScriptGlobalObject,
                        public nsIDOMJSWindow,
                        public nsIScriptObjectPrincipal,
-                       public nsIDOMEventTarget,
                        public nsIDOMStorageIndexedDB,
                        public nsSupportsWeakReference,
                        public nsIInterfaceRequestor,
-                       public nsWrapperCache,
                        public PRCListStr,
                        public nsIDOMWindowPerformance,
                        public nsITouchEventReceiver,
diff --git a/dom/base/nsPIWindowRoot.h b/dom/base/nsPIWindowRoot.h
index a11d5d18b7c..0c91ea46809 100644
--- a/dom/base/nsPIWindowRoot.h
+++ b/dom/base/nsPIWindowRoot.h
@@ -8,7 +8,7 @@
 #define nsPIWindowRoot_h__
 
 #include "nsISupports.h"
-#include "nsIDOMEventTarget.h"
+#include "mozilla/dom/EventTarget.h"
 
 class nsPIDOMWindow;
 class nsIControllers;
@@ -20,7 +20,7 @@ struct JSContext;
 { 0xc89780f2, 0x8905, 0x417f, \
   { 0xa6, 0x62, 0xf6, 0xc, 0xa6, 0xd7, 0xc, 0x91 } }
 
-class nsPIWindowRoot : public nsIDOMEventTarget
+class nsPIWindowRoot : public mozilla::dom::EventTarget
 {
 public:
   NS_DECLARE_STATIC_IID_ACCESSOR(NS_IWINDOWROOT_IID)
diff --git a/dom/base/nsWindowRoot.cpp b/dom/base/nsWindowRoot.cpp
index e508436ad5d..2db8339054a 100644
--- a/dom/base/nsWindowRoot.cpp
+++ b/dom/base/nsWindowRoot.cpp
@@ -39,15 +39,17 @@ nsWindowRoot::~nsWindowRoot()
   }
 }
 
-NS_IMPL_CYCLE_COLLECTION_3(nsWindowRoot,
-                           mListenerManager,
-                           mPopupNode,
-                           mParent)
+NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE_3(nsWindowRoot,
+                                        mListenerManager,
+                                        mPopupNode,
+                                        mParent)
 
 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(nsWindowRoot)
+  NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
   NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIDOMEventTarget)
   NS_INTERFACE_MAP_ENTRY(nsPIWindowRoot)
   NS_INTERFACE_MAP_ENTRY(nsIDOMEventTarget)
+  NS_INTERFACE_MAP_ENTRY(mozilla::dom::EventTarget)
 NS_INTERFACE_MAP_END
 
 NS_IMPL_CYCLE_COLLECTING_ADDREF(nsWindowRoot)
diff --git a/dom/base/nsWindowRoot.h b/dom/base/nsWindowRoot.h
index fde82072d91..88609005e63 100644
--- a/dom/base/nsWindowRoot.h
+++ b/dom/base/nsWindowRoot.h
@@ -45,7 +45,8 @@ public:
   }
   virtual nsIDOMEventTarget* GetParentTarget() { return mParent; }
 
-  NS_DECL_CYCLE_COLLECTION_CLASS_AMBIGUOUS(nsWindowRoot, nsIDOMEventTarget)
+  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS_AMBIGUOUS(nsWindowRoot,
+                                                         nsIDOMEventTarget)
 
 protected:
   // Members