Oilpan: Allocate all EventTarget derived types on the manged heap.

Source/modules/notifications/Notification.h

 /*
  * Copyright (C) 2013 Google Inc. 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
@@ skipping 32 matching lines @@
 #include "wtf/RefCounted.h"
 
 namespace WebCore {
 
 class Dictionary;
 class ExecutionContext;
 class NotificationPermissionCallback;
 
 class Notification : public RefCountedGarbageCollected<Notification>, public ScriptWrappable, public ActiveDOMObject, public EventTargetWithInlineData {
     DEFINE_EVENT_TARGET_REFCOUNTING(RefCountedGarbageCollected<Notification>);
-
+    WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(Notification);
 public:
     static Notification* create(ExecutionContext*, const String& title, const Dictionary& options);
 
     virtual ~Notification();
 
     void close();
 
     DEFINE_ATTRIBUTE_EVENT_LISTENER(click);
     DEFINE_ATTRIBUTE_EVENT_LISTENER(show);
     DEFINE_ATTRIBUTE_EVENT_LISTENER(error);
@@ skipping 20 matching lines @@
 
     // EventTarget interface.
     virtual ExecutionContext* executionContext() const OVERRIDE FINAL { return ActiveDOMObject::executionContext(); }
     virtual bool dispatchEvent(PassRefPtrWillBeRawPtr<Event>) OVERRIDE FINAL;
     virtual const AtomicString& interfaceName() const OVERRIDE;
 
     // ActiveDOMObject interface.
     virtual void stop() OVERRIDE;
     virtual bool hasPendingActivity() const OVERRIDE;
 
-    void trace(Visitor*) { }
-
 private:
     Notification(const String& title, ExecutionContext*, NotificationClient*);
 
     // Calling show() may start asynchronous operation. If this object has
     // a V8 wrapper, hasPendingActivity() prevents the wrapper from being
     // collected while m_state is Showing, and so this instance stays alive
     // until the operation completes. Otherwise, you need to hold a ref on this
     // instance until the operation completes.
     void show();
 
@@ skipping 21 matching lines @@
     NotificationState m_state;
 
     NotificationClient* m_client;
 
     OwnPtr<AsyncMethodRunner<Notification> > m_asyncRunner;
 };
 
 } // namespace WebCore
 
 #endif // Notification_h