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

cc/layers/viewport.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CC_LAYERS_VIEWPORT_H_
 #define CC_LAYERS_VIEWPORT_H_
 
 #include <memory>
 
 #include "base/gtest_prod_util.h"
@@ skipping 32 matching lines @@
 
   // Scrolls the viewport, applying the unique bubbling between the inner and
   // outer viewport. Scrolls can be consumed by top controls.
   ScrollResult ScrollBy(const gfx::Vector2dF& delta,
                         const gfx::Point& viewport_point,
                         bool is_wheel_scroll,
                         bool affect_top_controls);
 
   // 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::TimeDelta delayed_by);
 
   void PinchUpdate(float magnify_delta, const gfx::Point& anchor);
   void PinchEnd();
 
  private:
   explicit Viewport(LayerTreeHostImpl* host_impl);
 
   // Returns true if viewport_delta is stricly less than pending_delta.
   static bool ShouldAnimateViewport(const gfx::Vector2dF& viewport_delta,
                                     const gfx::Vector2dF& pending_delta);
@@ skipping 20 matching lines @@
   gfx::Vector2d pinch_anchor_adjustment_;
 
   FRIEND_TEST_ALL_PREFIXES(ViewportTest, ShouldAnimateViewport);
 
   DISALLOW_COPY_AND_ASSIGN(Viewport);
 };
 
 }  // namespace cc
 
 #endif  // CC_LAYERS_VIEWPORT_H_