content: Cleanup class/struct forward declarations

content/renderer/pepper/ppb_video_decoder_impl.h

 // Copyright (c) 2012 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_PPB_VIDEO_DECODER_IMPL_H_
 #define CONTENT_RENDERER_PEPPER_PPB_VIDEO_DECODER_IMPL_H_
 
 #include <stdint.h>
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "media/video/video_decode_accelerator.h"
 #include "ppapi/c/dev/pp_video_dev.h"
 #include "ppapi/c/dev/ppp_video_decoder_dev.h"
 #include "ppapi/c/pp_var.h"
 #include "ppapi/shared_impl/ppb_video_decoder_shared.h"
 #include "ppapi/shared_impl/resource.h"
 #include "ppapi/thunk/ppb_video_decoder_dev_api.h"
 
 struct PP_PictureBuffer_Dev;
 struct PP_VideoBitstreamBuffer_Dev;
 
 namespace content {
-class PPB_Graphics3D_Impl;
 
 class PPB_VideoDecoder_Impl : public ppapi::PPB_VideoDecoder_Shared,
                               public media::VideoDecodeAccelerator::Client {
  public:
   // See PPB_VideoDecoder_Dev::Create.  Returns 0 on failure to create &
   // initialize.
   static PP_Resource Create(PP_Instance instance,
                             PP_Resource graphics_context,
                             PP_VideoDecoder_Profile profile);
 
@@ skipping 40 matching lines @@
   // The interface to use when making calls on the plugin. For the most part,
   // methods should not use this directly but should call GetPPP() instead.
   const PPP_VideoDecoder_Dev* ppp_videodecoder_;
 
   DISALLOW_COPY_AND_ASSIGN(PPB_VideoDecoder_Impl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_PEPPER_PPB_VIDEO_DECODER_IMPL_H_