chrome: Cleanup class/struct forward declarations

chrome/renderer/extensions/cast_streaming_native_handler.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_RENDERER_EXTENSIONS_CAST_STREAMING_NATIVE_HANDLER_H_
 #define CHROME_RENDERER_EXTENSIONS_CAST_STREAMING_NATIVE_HANDLER_H_
 
 #include <map>
 #include <memory>
 
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "extensions/renderer/object_backed_native_handler.h"
 #include "v8/include/v8.h"
 
 class CastRtpStream;
 class CastUdpTransport;
 
 namespace base {
 class BinaryValue;
 class DictionaryValue;
 }
 
-namespace blink {
-class WebMediaStream;
-}
-
 namespace net {
 class IPEndPoint;
 }
 
 namespace media {
 class AudioCapturerSource;
 class AudioParameters;
 class VideoCapturerSource;
 namespace cast {
 struct FrameReceiverConfig;
@@ skipping 106 matching lines @@
   RtpStreamCallbackMap get_stats_callbacks_;
 
   base::WeakPtrFactory<CastStreamingNativeHandler> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(CastStreamingNativeHandler);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_RENDERER_EXTENSIONS_CAST_STREAMING_NATIVE_HANDLER_H_