cc: Use HighResNow as timebase if it is fast and reliable

cc/scheduler/frame_rate_controller.cc

 // 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.
 
 #include "cc/scheduler/frame_rate_controller.h"
 
 #include "base/bind.h"
 #include "base/debug/trace_event.h"
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/single_thread_task_runner.h"
 #include "cc/scheduler/delay_based_time_source.h"
 #include "cc/scheduler/time_source.h"
+#include "ui/gfx/frame_time.h"
 
 namespace cc {
 
 class FrameRateControllerTimeSourceAdapter : public TimeSourceClient {
  public:
   static scoped_ptr<FrameRateControllerTimeSourceAdapter> Create(
       FrameRateController* frame_rate_controller) {
     return make_scoped_ptr(
         new FrameRateControllerTimeSourceAdapter(frame_rate_controller));
   }
@@ skipping 134 matching lines @@
   if (is_time_source_throttling_)
     return time_source_->NextTickTime();
 
   return base::TimeTicks();
 }
 
 base::TimeTicks FrameRateController::LastTickTime() {
   if (is_time_source_throttling_)
     return time_source_->LastTickTime();
 
-  return base::TimeTicks::Now();
+  return gfx::FrameTime::Now();
 }
 
 }  // namespace cc