WebAudio: Fix AudioNode leak in a case that AudioNode is not disconnected from the graph explicitly.

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 87 matching lines @@
 void AudioNode::dispose()
 {
     ASSERT(isMainThread());
     ASSERT(context()->isGraphOwner());
 
     context()->removeChangedChannelCountMode(this);
     context()->removeAutomaticPullNode(this);
     context()->disposeOutputs(*this);
     for (unsigned i = 0; i < m_outputs.size(); ++i)
         output(i)->disconnectAll();
+
+    if (context()->contextState() != AudioContext::Running)
+        return;
+    ThreadState::current()->markAsZombie(this);
+    context()->setLastZombie(this);
 }
 
 String AudioNode::nodeTypeName() const
 {
     switch (m_nodeType) {
     case NodeTypeDestination:
         return "AudioDestinationNode";
     case NodeTypeOscillator:
         return "OscillatorNode";
     case NodeTypeAudioBufferSource:
@@ skipping 485 matching lines @@
 
 void AudioNode::updateChannelCountMode()
 {
     m_channelCountMode = m_newChannelCountMode;
     updateChannelsForInputs();
 }
 
 } // namespace blink
 
 #endif // ENABLE(WEB_AUDIO)