Take MT jank into account when animating the scroll offset on CC

cc/trees/layer_tree_host_impl.cc

Index: cc/trees/layer_tree_host_impl.cc
diff --git a/cc/trees/layer_tree_host_impl.cc b/cc/trees/layer_tree_host_impl.cc
index 00c8e24da3a8142ff093e16d35459a2dfc9d2ed1..33d38fb698e00cba752b7aecc53872b0da0b284d 100644
--- a/cc/trees/layer_tree_host_impl.cc
+++ b/cc/trees/layer_tree_host_impl.cc
@@ -2818,6 +2818,15 @@ bool LayerTreeHostImpl::ScrollAnimationCreate(ScrollNode* scroll_node,
   return true;
 }
 
+void LayerTreeHostImpl::AdjustDuration(base::TimeDelta adjustment) {
+  ScrollTree& scroll_tree = active_tree_->property_trees()->scroll_tree;
+  ScrollNode* scroll_node = scroll_tree.CurrentlyScrollingNode();
+  if (scroll_node) {
+    animation_host_->ImplOnlyScrollAnimationAdjustDuration(
+        scroll_node->owner_id, adjustment);
+  }
+}
+
 InputHandler::ScrollStatus LayerTreeHostImpl::ScrollAnimated(
     const gfx::Point& viewport_point,
     const gfx::Vector2dF& scroll_delta) {