content: Cleanup class/struct forward declarations

content/renderer/media/webmediaplayer_ms.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 CONTENT_RENDERER_MEDIA_WEBMEDIAPLAYER_MS_H_
 #define CONTENT_RENDERER_MEDIA_WEBMEDIAPLAYER_MS_H_
 
 #include <memory>
 #include <string>
 
@@ skipping 30 matching lines @@
 namespace gles2 {
 class GLES2Interface;
 }
 }
 
 namespace content {
 class MediaStreamAudioRenderer;
 class MediaStreamRendererFactory;
 class MediaStreamVideoRenderer;
 class WebMediaPlayerMSCompositor;
-class RenderFrameObserver;
 
 // WebMediaPlayerMS delegates calls from WebCore::MediaPlayerPrivate to
 // Chrome's media player when "src" is from media stream.
 //
 // All calls to WebMediaPlayerMS methods must be from the main thread of
 // Renderer process.
 //
 // WebMediaPlayerMS works with multiple objects, the most important ones are:
 //
 // MediaStreamVideoRenderer
@@ skipping 175 matching lines @@
   // True if playback should be started upon the next call to OnShown(). Only
   // used on Android.
   bool should_play_upon_shown_;
 
   DISALLOW_COPY_AND_ASSIGN(WebMediaPlayerMS);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_MEDIA_WEBMEDIAPLAYER_MS_H_