Roll Chrome into Mojo.

cc/scheduler/delay_based_time_source.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_DELAY_BASED_TIME_SOURCE_H_
 #define CC_SCHEDULER_DELAY_BASED_TIME_SOURCE_H_
 
 #include <string>
 
 #include "base/memory/weak_ptr.h"
@@ skipping 77 matching lines @@
   bool active_;
 
   base::SingleThreadTaskRunner* task_runner_;
   base::WeakPtrFactory<DelayBasedTimeSource> weak_factory_;
 
  private:
   friend class base::RefCounted<DelayBasedTimeSource>;
   DISALLOW_COPY_AND_ASSIGN(DelayBasedTimeSource);
 };
 
-// DelayBasedTimeSource uses base::TimeTicks::HighResNow as its timebase.
+// DelayBasedTimeSource that once used base::TimeTicks::HighResNow as its time
+// source, but is now a no-op.
+// TODO(brianderson): Remove along with gfx::/FrameTime.http://crbug.com/447329
 class DelayBasedTimeSourceHighRes : public DelayBasedTimeSource {
  public:
   static scoped_refptr<DelayBasedTimeSourceHighRes> Create(
         base::TimeDelta interval, base::SingleThreadTaskRunner* task_runner);
 
   base::TimeTicks Now() const override;
 
  protected:
   DelayBasedTimeSourceHighRes(base::TimeDelta interval,
                               base::SingleThreadTaskRunner* task_runner);
   ~DelayBasedTimeSourceHighRes() override;
 
   std::string TypeString() const override;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(DelayBasedTimeSourceHighRes);
 };
 
 }  // namespace cc
 
 #endif  // CC_SCHEDULER_DELAY_BASED_TIME_SOURCE_H_