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

Source/modules/webaudio/AudioNode.cpp

 /*
  * Copyright (C) 2010, 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 574 matching lines @@
         fprintf(stderr, "%d: %d\n", i, s_nodeCount[i]);
 
     fprintf(stderr, "===========================\n\n\n");
 }
 
 #endif // DEBUG_AUDIONODE_REFERENCES
 
 void AudioNode::trace(Visitor* visitor)
 {
     visitor->trace(m_context);
+    EventTargetWithInlineData::trace(visitor);
 }
 
 #if ENABLE(OILPAN)
 void AudioNode::clearKeepAlive()
 {
     // It is safe to drop the self-persistent when the ref count
     // of a AudioNode reaches zero. At that point, the
     // AudioNode node is removed from the AudioContext and
     // it cannot be reattached. Therefore, the reference count
     // will not go above zero again.
     ASSERT(m_keepAlive);
     m_keepAlive = nullptr;
 }
 #endif
 
 } // namespace WebCore
 
 #endif // ENABLE(WEB_AUDIO)