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

Source/modules/mediastream/RTCDTMFSender.cpp

 /*
  * 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 152 matching lines @@
 
     WillBeHeapVector<RefPtrWillBeMember<Event> >::iterator it = events.begin();
     for (; it != events.end(); ++it)
         dispatchEvent((*it).release());
 }
 
 void RTCDTMFSender::trace(Visitor* visitor)
 {
     visitor->trace(m_track);
     visitor->trace(m_scheduledEvents);
+    EventTargetWithInlineData::trace(visitor);
 }
 
 } // namespace WebCore