Unify Android Webview and Chrome's fling

cc/trees/layer_tree_host_impl.h

Index: cc/trees/layer_tree_host_impl.h
diff --git a/cc/trees/layer_tree_host_impl.h b/cc/trees/layer_tree_host_impl.h
index dddf231af5075afa7999bb68f649a3414425bd54..6551255a04b13d0002bc1539006ef66c878f2431 100644
--- a/cc/trees/layer_tree_host_impl.h
+++ b/cc/trees/layer_tree_host_impl.h
@@ -185,7 +185,7 @@ class CC_EXPORT LayerTreeHostImpl
                                bool anchor_point,
                                float page_scale,
                                base::TimeDelta duration);
-  void SetNeedsAnimate() override;
+  void SetNeedsAnimateInput() override;
   bool IsCurrentlyScrollingLayerAt(const gfx::Point& viewport_point,
                                    InputHandler::ScrollInputType type) override;
   bool HaveWheelEventHandlersAt(const gfx::Point& viewport_point) override;
@@ -394,6 +394,7 @@ class CC_EXPORT LayerTreeHostImpl
   bool AnimationsAreVisible() { return visible() && CanDraw(); }
 
   void SetNeedsCommit() { client_->SetNeedsCommitOnImplThread(); }
+  void SetNeedsAnimate();
   void SetNeedsRedraw();
 
   ManagedMemoryPolicy ActualManagedMemoryPolicy() const;
@@ -599,6 +600,7 @@ class CC_EXPORT LayerTreeHostImpl
   // outer if the inner is at its scroll extents.
   void ScrollViewportInnerFirst(gfx::Vector2dF scroll_delta);
 
+  void AnimateInput(base::TimeTicks monotonic_time);
   void AnimatePageScale(base::TimeTicks monotonic_time);
   void AnimateScrollbars(base::TimeTicks monotonic_time);
   void AnimateTopControls(base::TimeTicks monotonic_time);
@@ -698,6 +700,8 @@ class CC_EXPORT LayerTreeHostImpl
 
   // The optional delegate for the root layer scroll offset.
   LayerScrollOffsetDelegate* root_layer_scroll_offset_delegate_;
+  LayerScrollOffsetDelegate::AnimationCallback root_layer_animation_callback_;
+
   const LayerTreeSettings settings_;
   LayerTreeDebugState debug_state_;
   bool visible_;