gfx: Add FrameTime and DisplayTime classes

cc/animation/scrollbar_animation_controller_linear_fade.h

Index: cc/animation/scrollbar_animation_controller_linear_fade.h
diff --git a/cc/animation/scrollbar_animation_controller_linear_fade.h b/cc/animation/scrollbar_animation_controller_linear_fade.h
index 85cdada51562208bba11889882a207ce601e8433..e6919483eb95404cfdbf2a2eaf55a437d08da6ca 100644
--- a/cc/animation/scrollbar_animation_controller_linear_fade.h
+++ b/cc/animation/scrollbar_animation_controller_linear_fade.h
@@ -24,14 +24,16 @@ class CC_EXPORT ScrollbarAnimationControllerLinearFade
 
   // ScrollbarAnimationController overrides.
   virtual bool IsAnimating() const OVERRIDE;
-  virtual base::TimeDelta DelayBeforeStart(base::TimeTicks now) const OVERRIDE;
+  virtual base::TimeDelta DelayBeforeStart(gfx::FrameTime now) const
+      OVERRIDE;
 
-  virtual bool Animate(base::TimeTicks now) OVERRIDE;
+  virtual bool Animate(gfx::FrameTime now) OVERRIDE;
   virtual void DidScrollGestureBegin() OVERRIDE;
-  virtual void DidScrollGestureEnd(base::TimeTicks now) OVERRIDE;
-  virtual void DidMouseMoveOffScrollbar(base::TimeTicks now) OVERRIDE;
-  virtual bool DidScrollUpdate(base::TimeTicks now) OVERRIDE;
-  virtual bool DidMouseMoveNear(base::TimeTicks now, float distance) OVERRIDE;
+  virtual void DidScrollGestureEnd(gfx::FrameTime now) OVERRIDE;
+  virtual void DidMouseMoveOffScrollbar(gfx::FrameTime now) OVERRIDE;
+  virtual bool DidScrollUpdate(gfx::FrameTime now) OVERRIDE;
+  virtual bool DidMouseMoveNear(gfx::FrameTime  now, float distance)
+      OVERRIDE;
 
  protected:
   ScrollbarAnimationControllerLinearFade(LayerImpl* scroll_layer,
@@ -39,12 +41,12 @@ class CC_EXPORT ScrollbarAnimationControllerLinearFade
                                          base::TimeDelta fadeout_length);
 
  private:
-  float OpacityAtTime(base::TimeTicks now);
+  float OpacityAtTime(gfx::FrameTime now);
   void ApplyOpacityToScrollbars(float opacity);
 
   LayerImpl* scroll_layer_;
 
-  base::TimeTicks last_awaken_time_;
+  gfx::FrameTime last_awaken_time_;
   bool scroll_gesture_in_progress_;
   bool scroll_gesture_has_scrolled_;