Cleanup namespace usage in public/platform/Web[A-M]*.h.

public/platform/WebAudioSourceProviderClient.h

 /*
  * Copyright (C) 2011, 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 16 matching lines @@
 
 namespace blink {
 
 class WebAudioSourceProviderClient {
 public:
     virtual void setFormat(size_t numberOfChannels, float sampleRate) = 0;
 protected:
     virtual ~WebAudioSourceProviderClient() { }
 };
 
-} // WebKit
+} // namespace blink
 
 #endif // WebAudioSourceProviderClient_h