chromecast: Cleanup class/struct fwd declarations

chromecast/renderer/cast_content_renderer_client.h

 // Copyright 2014 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 CHROMECAST_RENDERER_CAST_CONTENT_RENDERER_CLIENT_H_
 #define CHROMECAST_RENDERER_CAST_CONTENT_RENDERER_CLIENT_H_
 
 #include <vector>
 
 #include "base/macros.h"
 #include "build/build_config.h"
 #include "content/public/renderer/content_renderer_client.h"
 
-namespace IPC {
-class MessageFilter;
-}
-
 namespace network_hints {
 class PrescientNetworkingDispatcher;
 }  // namespace network_hints
 
 namespace chromecast {
 namespace media {
 class MediaCapsObserverImpl;
 }
 
 namespace shell {
-class CastGinRunner;
-class CastRenderThreadObserver;
 
 void ExecuteJavaScript(content::RenderFrame* render_frame, int resourceId);
 
 class CastContentRendererClient : public content::ContentRendererClient {
  public:
   // Creates an implementation of CastContentRendererClient. Platform should
   // link in an implementation as needed.
   static std::unique_ptr<CastContentRendererClient> Create();
 
   ~CastContentRendererClient() override;
@@ skipping 19 matching lines @@
   std::unique_ptr<media::MediaCapsObserverImpl> media_caps_observer_;
   const bool allow_hidden_media_playback_;
 
   DISALLOW_COPY_AND_ASSIGN(CastContentRendererClient);
 };
 
 }  // namespace shell
 }  // namespace chromecast
 
 #endif  // CHROMECAST_RENDERER_CAST_CONTENT_RENDERER_CLIENT_H_