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

cc/layers/viewport.h

Index: cc/layers/viewport.h
diff --git a/cc/layers/viewport.h b/cc/layers/viewport.h
index 2d603f253f263241a9c06a90b334316e5036ba51..c2e01ec5eb74361946b924b8ccc4bc18263852fd 100644
--- a/cc/layers/viewport.h
+++ b/cc/layers/viewport.h
@@ -50,7 +50,8 @@ class CC_EXPORT Viewport {
 
   // Scrolls the viewport, bubbling the delta between the inner and outer
   // viewport. Only animates either of the two viewports.
-  gfx::Vector2dF ScrollAnimated(const gfx::Vector2dF& delta);
+  gfx::Vector2dF ScrollAnimated(const gfx::Vector2dF& delta,
+                                base::TimeTicks original_event_time);
 
   void PinchUpdate(float magnify_delta, const gfx::Point& anchor);
   void PinchEnd();