Web Audio: Oilpan: Correctly trace m_referencedNodes elements within a lock.

Source/modules/webaudio/AudioContext.h

 /*
  * 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 280 matching lines @@
     // Oilpan: Since items are added to the vector by the audio thread (not registered to Oilpan),
     // we cannot use a HeapVector.
     GC_PLUGIN_IGNORE("http://crbug.com/404527")
     Vector<AudioNode*> m_finishedNodes;
 
     // List of source nodes. This is either accessed when the graph lock is
     // held, or on the main thread when the audio thread has finished.
     // Oilpan: This Vector holds connection references. We must call
     // AudioNode::makeConnection when we add an AudioNode to this, and must call
     // AudioNode::breakConnection() when we remove an AudioNode from this.
-    Member<HeapVector<Member<AudioNode>>> m_referencedNodes;
+    HeapVector<Member<AudioNode>> m_referencedNodes;
 
     // Stop rendering the audio graph.
     void stopRendering();
 
     // Handle Promises for resume() and suspend()
     void resolvePromisesForResume();
     void resolvePromisesForResumeOnMainThread();
 
     void resolvePromisesForSuspend();
     void resolvePromisesForSuspendOnMainThread();
@@ skipping 54 matching lines @@
     HashSet<AudioNode*> m_automaticPullNodes;
     GC_PLUGIN_IGNORE("http://crbug.com/404527")
     Vector<AudioNode*> m_renderingAutomaticPullNodes;
     // m_automaticPullNodesNeedUpdating keeps track if m_automaticPullNodes is modified.
     bool m_automaticPullNodesNeedUpdating;
     void updateAutomaticPullNodes();
 
     unsigned m_connectionCount;
 
     // Graph locking.
+    bool m_didInitializeContextGraphMutex;
     RecursiveMutex m_contextGraphMutex;
     volatile ThreadIdentifier m_audioThread;
 
     // Only accessed in the audio thread.
     // Oilpan: Since items are added to these vectors by the audio thread (not registered to Oilpan),
     // we cannot use HeapVectors.
     GC_PLUGIN_IGNORE("http://crbug.com/404527")
     Vector<AudioNode*> m_deferredBreakConnectionList;
 
     Member<AudioBuffer> m_renderTarget;
@@ skipping 11 matching lines @@
     HashSet<AudioNode*> m_deferredCountModeChange;
 
     // This is considering 32 is large enough for multiple channels audio.
     // It is somewhat arbitrary and could be increased if necessary.
     enum { MaxNumberOfChannels = 32 };
 };
 
 } // namespace blink
 
 #endif // AudioContext_h