cc: Use commit to activation time in repaint HUD

cc/debug/rendering_stats.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/rendering_stats.h"
 
 namespace cc {
 
 RenderingStats::TimeDeltaList::TimeDeltaList() {
 }
@@ skipping 10 matching lines @@
   std::list<base::TimeDelta>::const_iterator iter;
   for (iter = values.begin(); iter != values.end(); ++iter) {
     list_value->AppendDouble(iter->InMillisecondsF());
   }
 }
 
 void RenderingStats::TimeDeltaList::Add(const TimeDeltaList& other) {
   values.insert(values.end(), other.values.begin(), other.values.end());
 }
 
+base::TimeDelta RenderingStats::TimeDeltaList::GetLastTimeDelta() const {
+  return values.empty() ? base::TimeDelta() : values.back();
+}
+
 RenderingStats::MainThreadRenderingStats::MainThreadRenderingStats()
     : painted_pixel_count(0), recorded_pixel_count(0) {
 }
 
 RenderingStats::MainThreadRenderingStats::~MainThreadRenderingStats() {
 }
 
 scoped_refptr<base::debug::ConvertableToTraceFormat>
 RenderingStats::MainThreadRenderingStats::AsTraceableData() const {
   scoped_refptr<base::debug::TracedValue> record_data =
@@ skipping 79 matching lines @@
   commit_to_activate_duration_estimate.Add(
       other.commit_to_activate_duration_estimate);
 }
 
 void RenderingStats::Add(const RenderingStats& other) {
   main_stats.Add(other.main_stats);
   impl_stats.Add(other.impl_stats);
 }
 
 }  // namespace cc