cc: Cleanup class/struct forward declarations

cc/scheduler/scheduler_state_machine.h

 // Copyright 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 CC_SCHEDULER_SCHEDULER_STATE_MACHINE_H_
 #define CC_SCHEDULER_SCHEDULER_STATE_MACHINE_H_
 
 #include <memory>
 #include <string>
 
 #include "base/macros.h"
 #include "cc/base/cc_export.h"
 #include "cc/output/begin_frame_args.h"
 #include "cc/scheduler/commit_earlyout_reason.h"
 #include "cc/scheduler/draw_result.h"
 #include "cc/scheduler/scheduler_settings.h"
 #include "cc/tiles/tile_priority.h"
 
 namespace base {
 namespace trace_event {
 class ConvertableToTraceFormat;
 class TracedValue;
 }
-class Value;
 }
 
 namespace cc {
 
 enum class ScrollHandlerState {
   SCROLL_AFFECTS_SCROLL_HANDLER,
   SCROLL_DOES_NOT_AFFECT_SCROLL_HANDLER,
 };
 const char* ScrollHandlerStateToString(ScrollHandlerState state);
 
@@ skipping 310 matching lines @@
   bool did_draw_in_last_frame_;
   bool did_submit_in_last_frame_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(SchedulerStateMachine);
 };
 
 }  // namespace cc
 
 #endif  // CC_SCHEDULER_SCHEDULER_STATE_MACHINE_H_