Read compositor VSync information from platform, when possible

ash/wm/window_animations.cc

 // Copyright (c) 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 "ash/wm/window_animations.h"
 
 #include <math.h>
 
 #include <algorithm>
 #include <vector>
@@ skipping 268 matching lines @@
   }
   virtual void OnCompositingEnded(ui::Compositor* compositor) OVERRIDE {
   }
   virtual void OnCompositingAborted(ui::Compositor* compositor) OVERRIDE {
     // Triggers OnImplicitAnimationsCompleted() to be called and deletes us.
     layer_->GetAnimator()->StopAnimating();
   }
   virtual void OnCompositingLockStateChanged(
       ui::Compositor* compositor) OVERRIDE {
   }
-  virtual void OnUpdateVSyncParameters(ui::Compositor* compositor,
-                                       base::TimeTicks timebase,
-                                       base::TimeDelta interval) OVERRIDE {
-  }
 
   // aura::WindowObserver overrides:
   virtual void OnWindowDestroying(aura::Window* window) OVERRIDE {
     // Triggers OnImplicitAnimationsCompleted() to be called and deletes us.
     layer_->GetAnimator()->StopAnimating();
   }
   virtual void OnWindowRemovingFromRootWindow(aura::Window* window) OVERRIDE {
     layer_->GetAnimator()->StopAnimating();
   }
 
@@ skipping 238 matching lines @@
   }
 
   // Assume the shelf is overflowed, zoom off to the bottom right of the
   // work area.
   gfx::Rect work_area =
       Shell::GetScreen()->GetDisplayNearestWindow(window).work_area();
   return gfx::Rect(work_area.right(), work_area.bottom(), 0, 0);
 }
 
 }  // namespace ash