Implement fade-out animation for Aura overlay scrollbars (CC only).

cc/input/scrollbar_animation_controller.h

Index: cc/input/scrollbar_animation_controller.h
diff --git a/cc/input/scrollbar_animation_controller.h b/cc/input/scrollbar_animation_controller.h
index a3b6100bc52cb67897807d76f9f2f64707776f5d..64e4903bea73e3a1571c4d95f908c3ae7b01ba2f 100644
--- a/cc/input/scrollbar_animation_controller.h
+++ b/cc/input/scrollbar_animation_controller.h
@@ -61,17 +61,18 @@ class CC_EXPORT ScrollbarAnimationController {
 
   ScrollbarAnimationControllerClient* client_;
 
+  void PostDelayedAnimationTask(bool on_resize);
+
+  base::TimeDelta duration_;

[aelias_OOO_until_Jul13, 2016/10/20 23:40:51]

Could you replace this with a pure virtual getter, and move this state to
ScrollbarAnimationControllerLinearFade?

[bokan, 2016/10/21 00:32:30]

You mean move the state into both descendant classes right? Done.

+
  private:
   // Returns how far through the animation we are as a progress value from
   // 0 to 1.
   float AnimationProgressAtTime(base::TimeTicks now);
 
-  void PostDelayedAnimationTask(bool on_resize);
-
   base::TimeTicks last_awaken_time_;
   base::TimeDelta delay_before_starting_;
   base::TimeDelta resize_delay_before_starting_;
-  base::TimeDelta duration_;
 
   bool is_animating_;