Change LayerHostImpl to use frame time from BeginFrameArgs rather than ::Now()

cc/trees/layer_tree_host_impl.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_TREES_LAYER_TREE_HOST_IMPL_H_
 #define CC_TREES_LAYER_TREE_HOST_IMPL_H_
 
 #include <list>
 #include <set>
 #include <string>
@@ skipping 370 matching lines @@
     return accumulated_root_overscroll_;
   }
   gfx::Vector2dF current_fling_velocity() const {
     return current_fling_velocity_;
   }
 
   bool pinch_gesture_active() const { return pinch_gesture_active_; }
 
   void SetTreePriority(TreePriority priority);
 
-  void ResetCurrentFrameTimeForNextFrame();
-  virtual base::TimeTicks CurrentFrameTimeTicks();
-
-  virtual base::TimeTicks CurrentPhysicalTimeTicks() const;
+  virtual base::TimeTicks CurrentFrameTimeTicks() const;
+  virtual void OverrideCurrentFrameTime(base::TimeTicks frame_time);
 
   scoped_ptr<base::Value> AsValue() const { return AsValueWithFrame(NULL); }
   scoped_ptr<base::Value> AsValueWithFrame(FrameData* frame) const;
   scoped_ptr<base::Value> ActivationStateAsValue() const;
 
   bool page_scale_animation_active() const { return !!page_scale_animation_; }
 
   virtual void CreateUIResource(UIResourceId uid,
                                 const UIResourceBitmap& bitmap);
   // Deletes a UI resource.  May safely be called more than once.
@@ skipping 225 matching lines @@
   // (When these are specified, device_viewport_size_ remains used only for
   // scrollable size.)
   gfx::Transform external_transform_;
   gfx::Rect external_viewport_;
   gfx::Rect external_clip_;
   bool device_viewport_valid_for_tile_management_;
   bool external_stencil_test_enabled_;
 
   gfx::Rect viewport_damage_rect_;
 
-  base::TimeTicks current_frame_timeticks_;
+  BeginFrameArgs current_frame_args_;
+  BeginFrameArgs last_frame_args_;
 
   scoped_ptr<AnimationRegistrar> animation_registrar_;
 
   RenderingStatsInstrumentation* rendering_stats_instrumentation_;
   MicroBenchmarkControllerImpl micro_benchmark_controller_;
 
   bool need_to_update_visible_tiles_before_draw_;
 #ifndef NDEBUG
   bool did_lose_called_;
 #endif
 
   // Optional callback to notify of new tree activations.
   base::Closure tree_activation_callback_;
 
   SharedBitmapManager* shared_bitmap_manager_;
   int id_;
 
   std::set<SwapPromiseMonitor*> swap_promise_monitor_;
 
   DISALLOW_COPY_AND_ASSIGN(LayerTreeHostImpl);
 };
 
 }  // namespace cc
 
 #endif  // CC_TREES_LAYER_TREE_HOST_IMPL_H_