Oilpan: add [WillBeGarbageCollected] for Node.

Source/core/frame/DOMWindow.h

Index: Source/core/frame/DOMWindow.h
diff --git a/Source/core/frame/DOMWindow.h b/Source/core/frame/DOMWindow.h
index 4c065e403e66c37169e58cc8bcf05ba79b4c54c8..e69e46f06b64e250d98dd15bb7234ea84c671bf8 100644
--- a/Source/core/frame/DOMWindow.h
+++ b/Source/core/frame/DOMWindow.h
@@ -343,7 +343,19 @@ enum PageshowEventPersistence {
         void resetDOMWindowProperties();
         void willDestroyDocumentInFrame();
 
-        RefPtr<Document> m_document;
+        // FIXME: Oilpan: the need for this internal method will fall
+        // away when EventTargets are no longer using refcounts and
+        // window properties are also on the heap. Inline the minimal
+        // do-not-broadcast handling then and remove the enum +
+        // removeAllEventListenersInternal().
+        enum BroadcastListenerRemoval {
+            DoNotBroadcastListenerRemoval,
+            DoBroadcastListenerRemoval
+        };
+
+        void removeAllEventListenersInternal(BroadcastListenerRemoval);
+
+        RefPtrWillBeMember<Document> m_document;
 
         bool m_shouldPrintWhenFinishedLoading;
 #if ASSERT_ENABLED