Initialize DeferredTaskHandler's audio thread ID once.

third_party/WebKit/Source/modules/webaudio/AudioDestinationNode.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 43 matching lines @@
     // Need to check if the context actually alive. Otherwise the subsequent
     // steps will fail. If the context is not alive somehow, return immediately
     // and do nothing.
     //
     // TODO(hongchan): because the context can go away while rendering, so this
     // check cannot guarantee the safe execution of the following steps.
     ASSERT(context());
     if (!context())
         return;
 
-    context()->deferredTaskHandler().setAudioThread(currentThread());
+    context()->deferredTaskHandler().setAudioThreadToCurrentThread();
 
     // If the destination node is not initialized, pass the silence to the final
     // audio destination (one step before the FIFO). This check is for the case
     // where the destination is in the middle of tearing down process.
     if (!isInitialized()) {
         destinationBus->zero();
         return;
     }
 
     // Let the context take care of any business at the start of each render quantum.
@@ skipping 42 matching lines @@
     return static_cast<AudioDestinationHandler&>(handler());
 }
 
 unsigned long AudioDestinationNode::maxChannelCount() const
 {
     return audioDestinationHandler().maxChannelCount();
 }
 
 } // namespace blink