Read compositor VSync information from platform, when possible

ui/aura/bench/bench_main.cc

Index: ui/aura/bench/bench_main.cc
diff --git a/ui/aura/bench/bench_main.cc b/ui/aura/bench/bench_main.cc
index 94a8f6f2bfcb4be6ff43a03cc29d8d258762d108..4f59dd36267218f78f8ecbb87775f247738f4170 100644
--- a/ui/aura/bench/bench_main.cc
+++ b/ui/aura/bench/bench_main.cc
@@ -122,11 +122,6 @@ class BenchCompositorObserver : public ui::CompositorObserver {
   virtual void OnCompositingLockStateChanged(
       Compositor* compositor) OVERRIDE {}
 
-  virtual void OnUpdateVSyncParameters(ui::Compositor* compositor,
-                                       base::TimeTicks timebase,
-                                       base::TimeDelta interval) OVERRIDE {
-  }
-
   virtual void Draw() {}
 
   int frames() const { return frames_; }