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

webkit/plugins/ppapi/ppb_layer_compositor_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_LAYER_COMPOSITOR_IMPL_H_
 #define WEBKIT_PLUGINS_PPAPI_PPB_LAYER_COMPOSITOR_IMPL_H_
 
 #include "base/compiler_specific.h"
 #include "ppapi/thunk/ppb_layer_compositor_api.h"
 #include "ppapi/shared_impl/resource.h"
 
 struct PP_Rect;
-struct PP_Size;
 
 namespace webkit {
 namespace ppapi {
 
 class PPB_LayerCompositor_Impl
     : public ::ppapi::Resource,
       public ::ppapi::thunk::PPB_LayerCompositor_API {
  public:
   explicit PPB_LayerCompositor_Impl(PP_Instance instance);
   virtual ~PPB_LayerCompositor_Impl();
@@ skipping 13 matching lines @@
   virtual int32_t SwapBuffers(PP_CompletionCallback callback) OVERRIDE;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(PPB_LayerCompositor_Impl);
 };
 
 }  // namespace ppapi
 }  // namespace webkit
 
 #endif  // WEBKIT_PLUGINS_PPAPI_PPB_LAYER_COMPOSITOR_IMPL_H_