Update from https://crrev.com/305340

cc/trees/layer_tree_host_impl.h

 // Copyright 2011 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_TREES_LAYER_TREE_HOST_IMPL_H_
 #define CC_TREES_LAYER_TREE_HOST_IMPL_H_
 
 #include <list>
 #include <set>
 #include <string>
@@ skipping 128 matching lines @@
   void SetRootLayerScrollOffsetDelegate(
       LayerScrollOffsetDelegate* root_layer_scroll_offset_delegate) override;
   void OnRootLayerDelegatedScrollOffsetChanged() override;
   void ScrollEnd() override;
   InputHandler::ScrollStatus FlingScrollBegin() override;
   void MouseMoveAt(const gfx::Point& viewport_point) override;
   void PinchGestureBegin() override;
   void PinchGestureUpdate(float magnify_delta,
                           const gfx::Point& anchor) override;
   void PinchGestureEnd() override;
+  void StartPageScaleAnimation(const gfx::Vector2d& target_offset,
+                               bool anchor_point,
+                               float page_scale,
+                               base::TimeDelta duration);
   void SetNeedsAnimate() override;
   bool IsCurrentlyScrollingLayerAt(const gfx::Point& viewport_point,
                                    InputHandler::ScrollInputType type) override;
   bool HaveTouchEventHandlersAt(const gfx::Point& viewport_port) override;
   scoped_ptr<SwapPromiseMonitor> CreateLatencyInfoSwapPromiseMonitor(
       ui::LatencyInfo* latency) override;
   ScrollElasticityHelper* CreateScrollElasticityHelper() override;
 
   // TopControlsManagerClient implementation.
   void SetControlsTopOffset(float offset) override;
@@ skipping 546 matching lines @@
 
   bool requires_high_res_to_draw_;
   bool required_for_draw_tile_is_top_of_raster_queue_;
 
   DISALLOW_COPY_AND_ASSIGN(LayerTreeHostImpl);
 };
 
 }  // namespace cc
 
 #endif  // CC_TREES_LAYER_TREE_HOST_IMPL_H_