gfx: Add FrameTime and DisplayTime classes

cc/debug/frame_rate_counter.cc

 // Copyright 2012 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/debug/frame_rate_counter.h"
 
 #include <algorithm>
 #include <limits>
 
 #include "base/metrics/histogram.h"
@@ skipping 26 matching lines @@
 
 base::TimeDelta FrameRateCounter::RecentFrameInterval(size_t n) const {
   DCHECK_GT(n, 0u);
   DCHECK_LT(n, ring_buffer_.BufferSize());
   return ring_buffer_.ReadBuffer(n) - ring_buffer_.ReadBuffer(n - 1);
 }
 
 FrameRateCounter::FrameRateCounter(bool has_impl_thread)
     : has_impl_thread_(has_impl_thread), dropped_frame_count_(0) {}
 
-void FrameRateCounter::SaveTimeStamp(base::TimeTicks timestamp, bool software) {
+void FrameRateCounter::SaveTimeStamp(gfx::FrameTime timestamp, bool software) {
   ring_buffer_.SaveToBuffer(timestamp);
 
   // Check if frame interval can be computed.
   if (ring_buffer_.CurrentIndex() < 2)
     return;
 
   base::TimeDelta frame_interval_seconds =
       RecentFrameInterval(ring_buffer_.BufferSize() - 1);
 
   if (has_impl_thread_ && ring_buffer_.CurrentIndex() > 0) {
@@ skipping 81 matching lines @@
 
   if (frame_count) {
     DCHECK_GT(frame_times_total, 0.0);
     average_fps = frame_count / frame_times_total;
   }
 
   return average_fps;
 }
 
 }  // namespace cc