cc: Cleanup class/struct forward declarations

cc/surfaces/display_scheduler.h

 // Copyright 2015 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 CC_SURFACES_DISPLAY_SCHEDULER_H_
 #define CC_SURFACES_DISPLAY_SCHEDULER_H_
 
 #include <memory>
 
 #include "base/cancelable_callback.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/single_thread_task_runner.h"
 #include "cc/output/renderer_settings.h"
 #include "cc/scheduler/begin_frame_source.h"
 #include "cc/surfaces/surface_id.h"
 #include "cc/surfaces/surfaces_export.h"
 
 namespace cc {
 
-class OutputSurface;
 class BeginFrameSource;
 
 class CC_SURFACES_EXPORT DisplaySchedulerClient {
  public:
   virtual ~DisplaySchedulerClient() {}
 
   virtual bool DrawAndSwap() = 0;
 };
 
 class CC_SURFACES_EXPORT DisplayScheduler : public BeginFrameObserverBase {
@@ skipping 67 matching lines @@
 
   base::WeakPtrFactory<DisplayScheduler> weak_ptr_factory_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(DisplayScheduler);
 };
 
 }  // namespace cc
 
 #endif  // CC_SURFACES_DISPLAY_SCHEDULER_H_