HTMLMediaElement::clearMediaPlayer should acquire MediaElementAudioSourceNode::lock()

Source/core/html/HTMLMediaElement.h

 /*
  * Copyright (C) 2007, 2008, 2009, 2010, 2011, 2012, 2013 Apple 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 377 matching lines @@
     void scheduleTimeupdateEvent(bool periodicEvent);
     void scheduleEvent(const AtomicString& eventName);
 
     // loading
     void selectMediaResource();
     void loadResource(const KURL&, ContentType&, const String& keySystem);
     void scheduleNextSourceChild();
     void loadNextSourceChild();
     void userCancelledLoad();
     void clearMediaPlayer(int flags);
+    void clearMediaPlayerAndAudioSourceProviderClient();
     bool havePotentialSourceChild();
     void noneSupported();
     void mediaEngineError(PassRefPtr<MediaError> err);
     void cancelPendingEventsAndCallbacks();
     void waitForSourceChange();
     void prepareToPlay();
 
     KURL selectNextSourceChild(ContentType*, String* keySystem, InvalidURLAction);
 
     void mediaLoadingFailed(MediaPlayer::NetworkState);
@@ skipping 187 matching lines @@
 inline bool isHTMLMediaElement(const Node& node)
 {
     return node.isElementNode() && toElement(node).isMediaElement();
 }
 
 DEFINE_NODE_TYPE_CASTS_WITH_FUNCTION(HTMLMediaElement);
 
 } //namespace
 
 #endif