cancel overlay-scrollbar hover state when moving pointer out of window for ChromeOS

cc/input/scrollbar_animation_controller_thinning.cc

Index: cc/input/scrollbar_animation_controller_thinning.cc
diff --git a/cc/input/scrollbar_animation_controller_thinning.cc b/cc/input/scrollbar_animation_controller_thinning.cc
index 4324a4347bf32943698961ea04265905845f8ff1..20ffa639657e4f1be8879b8df8e6ca69ad91dec8 100644
--- a/cc/input/scrollbar_animation_controller_thinning.cc
+++ b/cc/input/scrollbar_animation_controller_thinning.cc
@@ -134,6 +134,23 @@ void ScrollbarAnimationControllerThinning::DidMouseMoveNear(float distance) {
   }
 }
 
+void ScrollbarAnimationControllerThinning::DidMouseLeave() {
+  if (captured_)
+    return;
+
+  if (mouse_is_over_scrollbar_) {
+    mouse_is_over_scrollbar_ = false;
+    opacity_change_ = DECREASE;

[dtapuska, 2016/10/04 20:16:22]

Is it possible that the mouse_is_over_scrollbar_ and !mouse_is_near_scrollbar_ 
which then the animation to hide it never kicks off?

[chaopeng, 2016/10/04 20:48:10]

I have a issue have, should move StartAnimation out. 

+  }
+
+  if (mouse_is_near_scrollbar_) {
+    mouse_is_near_scrollbar_ = false;
+    thickness_change_ = DECREASE;
+
+    StartAnimation();
+  }
+}
+
 float ScrollbarAnimationControllerThinning::OpacityAtAnimationProgress(
     float progress) {
   if (opacity_change_ == NONE)