Add an ASSERT to verify that AudioNode::dispose() is always called

Source/modules/webaudio/AudioNode.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 210 matching lines @@
 
 #if !ENABLE(OILPAN)
     // Ref-counting
     volatile int m_normalRefCount;
 #endif
     volatile int m_connectionRefCount;
 
     bool m_isMarkedForDeletion;
     bool m_isDisabled;
 
+#if ENABLE(ASSERT)
+    bool m_didCallDispose;
+#endif
+
 #if DEBUG_AUDIONODE_REFERENCES
     static bool s_isNodeCountInitialized;
     static int s_nodeCount[NodeTypeEnd];
 #endif
     static unsigned s_instanceCount;
 
 #if !ENABLE(OILPAN)
     virtual void refEventTarget() OVERRIDE FINAL { ref(); }
     virtual void derefEventTarget() OVERRIDE FINAL { deref(); }
 #endif
 
 protected:
     unsigned m_channelCount;
     ChannelCountMode m_channelCountMode;
     AudioBus::ChannelInterpretation m_channelInterpretation;
 };
 
 } // namespace blink
 
 #endif // AudioNode_h