Plumb smooth scrolling in Chromium compositor

content/renderer/input/input_handler_proxy_client.h

 // Copyright 2013 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 CONTENT_RENDERER_INPUT_INPUT_HANDLER_PROXY_CLIENT_H_
 #define CONTENT_RENDERER_INPUT_INPUT_HANDLER_PROXY_CLIENT_H_
 
 namespace blink {
 class WebGestureCurve;
 struct WebActiveWheelFlingParameters;
@@ skipping 16 matching lines @@
   virtual void TransferActiveWheelFlingAnimation(
       const blink::WebActiveWheelFlingParameters& params) = 0;
 
   // Creates a new fling animation curve instance for device |device_source|
   // with |velocity| and already scrolled |cumulative_scroll| pixels.
   virtual blink::WebGestureCurve* CreateFlingAnimationCurve(
       blink::WebGestureDevice device_source,
       const blink::WebFloatPoint& velocity,
       const blink::WebSize& cumulative_scroll) = 0;
 
+  // Creates a new smooth scrolling curve instance for device |device_source|
+  // starting at (|start_x|, |start_y|), ending at (|start_x| + |dx|, |start_y|
+  // + |dy|)
+  virtual blink::WebGestureCurve* CreateSmoothScrollAnimationCurve(
+      blink::WebGestureDevice deviceSource,
+      float start_x,
+      float start_y,
+      float dx,
+      float dy,
+      long duration) = 0;
+
   virtual void DidOverscroll(const DidOverscrollParams& params) = 0;
 
   virtual void DidStopFlinging() = 0;
 
   virtual void DidAnimateForInput() = 0;
 
  protected:
   virtual ~InputHandlerProxyClient() {}
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_INPUT_INPUT_HANDLER_PROXY_CLIENT_H_