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

Source/modules/mediastream/RTCDTMFSender.h

Index: Source/modules/mediastream/RTCDTMFSender.h
diff --git a/Source/modules/mediastream/RTCDTMFSender.h b/Source/modules/mediastream/RTCDTMFSender.h
index 712966bfdd21475a1f8c6eec8bfafdc3a8a9d41e..bbc123a56f9700abd147153dc87670ec11a4db06 100644
--- a/Source/modules/mediastream/RTCDTMFSender.h
+++ b/Source/modules/mediastream/RTCDTMFSender.h
@@ -43,8 +43,9 @@ namespace WebCore {
 class ExceptionState;
 class MediaStreamTrack;
 
-class RTCDTMFSender FINAL : public RefCounted<RTCDTMFSender>, public ScriptWrappable, public EventTargetWithInlineData, public blink::WebRTCDTMFSenderHandlerClient, public ActiveDOMObject {
+class RTCDTMFSender FINAL : public RefCountedWillBeRefCountedGarbageCollected<RTCDTMFSender>, public ScriptWrappable, public EventTargetWithInlineData, public blink::WebRTCDTMFSenderHandlerClient, public ActiveDOMObject {
     REFCOUNTED_EVENT_TARGET(RTCDTMFSender);
+    WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(RTCDTMFSender);
 public:
     static PassRefPtr<RTCDTMFSender> create(ExecutionContext*, blink::WebRTCPeerConnectionHandler*, PassRefPtr<MediaStreamTrack>, ExceptionState&);
     virtual ~RTCDTMFSender();
@@ -68,6 +69,8 @@ public:
     // ActiveDOMObject
     virtual void stop() OVERRIDE;
 
+    virtual void trace(Visitor*) OVERRIDE;
+
 private:
     RTCDTMFSender(ExecutionContext*, PassRefPtr<MediaStreamTrack>, PassOwnPtr<blink::WebRTCDTMFSenderHandler>);
 
@@ -86,7 +89,7 @@ private:
     bool m_stopped;
 
     Timer<RTCDTMFSender> m_scheduledEventTimer;
-    WillBePersistentHeapVector<RefPtrWillBeMember<Event> > m_scheduledEvents;
+    WillBeHeapVector<RefPtrWillBeMember<Event> > m_scheduledEvents;
 };
 
 } // namespace WebCore