content: Cleanup class/struct forward declarations

content/renderer/pepper/pepper_video_encoder_host.h

 // Copyright 2015 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_PEPPER_PEPPER_VIDEO_ENCODER_HOST_H_
 #define CONTENT_RENDERER_PEPPER_PEPPER_VIDEO_ENCODER_HOST_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <memory>
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_vector.h"
 #include "content/common/content_export.h"
 #include "gpu/command_buffer/client/gpu_control_client.h"
 #include "media/video/video_encode_accelerator.h"
 #include "ppapi/c/pp_codecs.h"
 #include "ppapi/c/ppb_video_frame.h"
 #include "ppapi/host/host_message_context.h"
 #include "ppapi/host/resource_host.h"
 #include "ppapi/proxy/resource_message_params.h"
 #include "ppapi/shared_impl/media_stream_buffer_manager.h"
 
 namespace gpu {
 class CommandBufferProxyImpl;
-class GpuChannelHost;
-}
-
-namespace media {
-class GpuVideoAcceleratorFactories;
 }
 
 namespace content {
 
 class RendererPpapiHost;
 class VideoEncoderShim;
 
 class CONTENT_EXPORT PepperVideoEncoderHost
     : public ppapi::host::ResourceHost,
       public media::VideoEncodeAccelerator::Client,
@@ skipping 131 matching lines @@
 #endif
 
   base::WeakPtrFactory<PepperVideoEncoderHost> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(PepperVideoEncoderHost);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_PEPPER_PEPPER_VIDEO_ENCODER_HOST_H_