Fix scrollbar fade animation scheduling.

cc/trees/layer_tree_impl.cc

Index: cc/trees/layer_tree_impl.cc
diff --git a/cc/trees/layer_tree_impl.cc b/cc/trees/layer_tree_impl.cc
index 6180568e8e926ca86d472f4368c1c39fa308711d..f47c78010d6bc49dfddf9d38eae436a9d45dbfb5 100644
--- a/cc/trees/layer_tree_impl.cc
+++ b/cc/trees/layer_tree_impl.cc
@@ -156,7 +156,7 @@ void LayerTreeImpl::SetCurrentlyScrollingLayer(LayerImpl* layer) {
   if (currently_scrolling_layer_ &&
       currently_scrolling_layer_->scrollbar_animation_controller())
     currently_scrolling_layer_->scrollbar_animation_controller()->
-        DidScrollGestureEnd(CurrentFrameTimeTicks());
+        DidScrollGestureEnd(CurrentPhysicalTimeTicks());
   currently_scrolling_layer_ = layer;
   if (layer && layer->scrollbar_animation_controller())
     layer->scrollbar_animation_controller()->DidScrollGestureBegin();
@@ -468,6 +468,10 @@ base::Time LayerTreeImpl::CurrentFrameTime() const {
   return layer_tree_host_impl_->CurrentFrameTime();
 }
 
+base::TimeTicks LayerTreeImpl::CurrentPhysicalTimeTicks() const {
+  return layer_tree_host_impl_->CurrentPhysicalTimeTicks();
+}
+
 void LayerTreeImpl::SetNeedsCommit() {
   layer_tree_host_impl_->SetNeedsCommit();
 }