content: Cleanup class/struct forward declarations

content/renderer/child_frame_compositing_helper.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 CONTENT_RENDERER_CHILD_FRAME_COMPOSITING_HELPER_H_
 #define CONTENT_RENDERER_CHILD_FRAME_COMPOSITING_HELPER_H_
 
 #include <stdint.h>
 
 #include <memory>
 #include <string>
 #include <vector>
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/shared_memory.h"
 #include "base/memory/weak_ptr.h"
 #include "cc/surfaces/surface_id.h"
 #include "content/common/content_export.h"
 #include "ui/gfx/geometry/size.h"
 
-namespace base {
-class SharedMemory;
-}
-
 namespace cc {
 struct SurfaceSequence;
 
 class CompositorFrame;
 class Layer;
-class SolidColorLayer;
-class SurfaceLayer;
 }
 
 namespace blink {
 class WebFrame;
 class WebPluginContainer;
 class WebLayer;
 }
 
 namespace gfx {
-class Rect;
 class Size;
 }
 
-struct FrameHostMsg_CompositorFrameSwappedACK_Params;
-struct FrameHostMsg_ReclaimCompositorResources_Params;
-
 namespace content {
 
 class BrowserPlugin;
-class BrowserPluginManager;
 class RenderFrameProxy;
 class ThreadSafeSender;
 
 class CONTENT_EXPORT ChildFrameCompositingHelper
     : public base::RefCounted<ChildFrameCompositingHelper> {
  public:
   static ChildFrameCompositingHelper* CreateForBrowserPlugin(
       const base::WeakPtr<BrowserPlugin>& browser_plugin);
   static ChildFrameCompositingHelper* CreateForRenderFrameProxy(
       RenderFrameProxy* render_frame_proxy);
@@ skipping 59 matching lines @@
   std::unique_ptr<blink::WebLayer> web_layer_;
   cc::SurfaceId surface_id_;
   blink::WebFrame* frame_;
 
   DISALLOW_COPY_AND_ASSIGN(ChildFrameCompositingHelper);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_CHILD_FRAME_COMPOSITING_HELPER_H_