Fix "unused variable" warnings.

cc/scheduler/begin_frame_source.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 CC_SCHEDULER_BEGIN_FRAME_SOURCE_H_
 #define CC_SCHEDULER_BEGIN_FRAME_SOURCE_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 137 matching lines @@
   // This notifies that the subclass that it must turn on or off its mechnanism
   // for producing BeginFrames.
   virtual void OnNeedsBeginFramesChanged(bool needs_begin_frames) {}
 
   bool needs_begin_frames() const { return !observers_.empty(); }
 
   std::set<BeginFrameObserver*> observers_;
   bool paused_;
 
  private:
-  bool inside_as_value_into_;
-
   DISALLOW_COPY_AND_ASSIGN(BeginFrameSourceBase);
 };
 
 // A frame source which calls BeginFrame (at the next possible time) as soon as
 // remaining frames reaches zero.
 class CC_EXPORT BackToBackBeginFrameSource : public BeginFrameSourceBase {
  public:
   explicit BackToBackBeginFrameSource(
       base::SingleThreadTaskRunner* task_runner);
   ~BackToBackBeginFrameSource() override;
@@ skipping 51 matching lines @@
   base::TimeTicks last_timebase_;
   base::TimeDelta authoritative_interval_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(SyntheticBeginFrameSource);
 };
 
 }  // namespace cc
 
 #endif  // CC_SCHEDULER_BEGIN_FRAME_SOURCE_H_