Read compositor VSync information from platform, when possible

ui/compositor/layer_unittest.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 "base/basictypes.h"
 #include "base/bind.h"
 #include "base/compiler_specific.h"
 #include "base/debug/trace_event.h"
 #include "base/file_util.h"
 #include "base/files/file_path.h"
@@ skipping 336 matching lines @@
     ended_ = true;
   }
 
   virtual void OnCompositingAborted(Compositor* compositor) OVERRIDE {
     aborted_ = true;
   }
 
   virtual void OnCompositingLockStateChanged(Compositor* compositor) OVERRIDE {
   }
 
-  virtual void OnUpdateVSyncParameters(Compositor* compositor,
-                                       base::TimeTicks timebase,
-                                       base::TimeDelta interval) OVERRIDE {
-  }
-
   bool committed_;
   bool started_;
   bool ended_;
   bool aborted_;
 
   DISALLOW_COPY_AND_ASSIGN(TestCompositorObserver);
 };
 
 }  // namespace
 
@@ skipping 1144 matching lines @@
   l1->SetOpacity(0.5f);
 
   // Change l1's cc::Layer.
   l1->SwitchCCLayerForTest();
 
   // Ensure that the opacity animation completed.
   EXPECT_FLOAT_EQ(l1->opacity(), 0.5f);
 }
 
 }  // namespace ui