cc: Use commit to activation time in repaint HUD

cc/debug/rendering_stats.h

 // 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.
 
 #ifndef CC_DEBUG_RENDERING_STATS_H_
 #define CC_DEBUG_RENDERING_STATS_H_
 
 #include <list>
 
 #include "base/basictypes.h"
@@ skipping 10 matching lines @@
   class CC_EXPORT TimeDeltaList {
    public:
     TimeDeltaList();
     ~TimeDeltaList();
 
     void Append(base::TimeDelta value);
     void AddToTracedValue(base::debug::TracedValue* list_value) const;
 
     void Add(const TimeDeltaList& other);
 
+    base::TimeDelta GetLastTimeDelta() const;
+
    private:
     std::list<base::TimeDelta> values;
   };
 
   struct CC_EXPORT MainThreadRenderingStats {
     // Note: when adding new members, please remember to update Add in
     // rendering_stats.cc.
 
     base::TimeDelta paint_time;
     int64 painted_pixel_count;
@@ skipping 35 matching lines @@
   MainThreadRenderingStats main_stats;
   ImplThreadRenderingStats impl_stats;
 
   // Add fields of |other| to the fields in this structure.
   void Add(const RenderingStats& other);
 };
 
 }  // namespace cc
 
 #endif  // CC_DEBUG_RENDERING_STATS_H_