Cleanup: Remove unneeded forward declarations in webkit/plugins/.

webkit/plugins/ppapi/ppb_video_layer_impl.h

 // Copyright (c) 2011 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 WEBKIT_PLUGINS_PPAPI_PPB_VIDEO_LAYER_IMPL_H_
 #define WEBKIT_PLUGINS_PPAPI_PPB_VIDEO_LAYER_IMPL_H_
 
 #include "base/compiler_specific.h"
 #include "ppapi/shared_impl/resource.h"
 #include "ppapi/thunk/ppb_video_layer_api.h"
 
-struct PP_Rect;
-struct PP_Size;
-
 namespace webkit {
 namespace ppapi {
 
 class PPB_VideoLayer_Impl : public ::ppapi::Resource,
                             public ::ppapi::thunk::PPB_VideoLayer_API {
  public:
   virtual ~PPB_VideoLayer_Impl();
 
   static PP_Resource Create(PP_Instance instance,
                             PP_VideoLayerMode_Dev mode);
 
   // Resource override.
   virtual PPB_VideoLayer_API* AsPPB_VideoLayer_API() OVERRIDE;
 
   // Derived classes must implement PPB_VideoLayer_API.
 
  protected:
   explicit PPB_VideoLayer_Impl(PP_Instance instance);
 
  private:
   DISALLOW_COPY_AND_ASSIGN(PPB_VideoLayer_Impl);
 };
 
 }  // namespace ppapi
 }  // namespace webkit
 
 #endif  // WEBKIT_PLUGINS_PPAPI_PPB_VIDEO_LAYER_IMPL_H_