content: Cleanup class/struct forward declarations

content/renderer/android/synchronous_compositor_frame_sink.h

 // Copyright 2013 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_ANDROID_SYNCHRONOUS_COMPOSITOR_FRAME_SINK_H_
 #define CONTENT_RENDERER_ANDROID_SYNCHRONOUS_COMPOSITOR_FRAME_SINK_H_
 
 #include <stddef.h>
 
 #include <memory>
 
 #include "base/callback.h"
 #include "base/cancelable_callback.h"
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/threading/thread_checker.h"
 #include "cc/output/compositor_frame.h"
 #include "cc/output/compositor_frame_sink.h"
 #include "cc/output/managed_memory_policy.h"
 #include "cc/surfaces/display_client.h"
 #include "cc/surfaces/surface_factory_client.h"
 #include "ipc/ipc_message.h"
 #include "ui/gfx/transform.h"
 
 class SkCanvas;
 
 namespace cc {
 class ContextProvider;
-class CompositorFrameMetadata;
 class Display;
 class SurfaceFactory;
 class SurfaceIdAllocator;
 class SurfaceManager;
 }
 
 namespace IPC {
 class Message;
 class Sender;
 }
 
 namespace content {
 
 class FrameSwapMessageQueue;
 class SynchronousCompositorRegistry;
-class WebGraphicsContext3DCommandBufferImpl;
 
 class SynchronousCompositorFrameSinkClient {
  public:
   virtual void DidActivatePendingTree() = 0;
   virtual void Invalidate() = 0;
   virtual void SubmitCompositorFrame(uint32_t compositor_frame_sink_id,
                                      cc::CompositorFrame frame) = 0;
 
  protected:
   virtual ~SynchronousCompositorFrameSinkClient() {}
@@ skipping 105 matching lines @@
   gfx::Rect sw_viewport_for_current_draw_;
 
   base::ThreadChecker thread_checker_;
 
   DISALLOW_COPY_AND_ASSIGN(SynchronousCompositorFrameSink);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_ANDROID_SYNCHRONOUS_COMPOSITOR_FRAME_SINK_H_