blink: Cleanup class forward declarations

third_party/WebKit/Source/platform/mediastream/MediaStreamCenter.h

 /*
  * Copyright 2014 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
@@ skipping 28 matching lines @@
 #include "wtf/text/WTFString.h"
 #include <memory>
 
 namespace blink {
 
 class AudioSourceProvider;
 class MediaStreamComponent;
 class MediaStreamDescriptor;
 class WebMediaStream;
 class WebMediaStreamCenter;
-class WebMediaStreamTrack;
 
 class PLATFORM_EXPORT MediaStreamCenter final
     : public WebMediaStreamCenterClient {
   USING_FAST_MALLOC(MediaStreamCenter);
   WTF_MAKE_NONCOPYABLE(MediaStreamCenter);
 
  public:
   ~MediaStreamCenter() override;
 
   static MediaStreamCenter& instance();
@@ skipping 15 matching lines @@
 
  private:
   MediaStreamCenter();
 
   std::unique_ptr<WebMediaStreamCenter> m_private;
 };
 
 }  // namespace blink
 
 #endif  // MediaStreamCenter_h