Move overscroll bounce to impl thread

cc/input/input_handler.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_INPUT_INPUT_HANDLER_H_
 #define CC_INPUT_INPUT_HANDLER_H_
 
 #include "base/basictypes.h"
 #include "base/time/time.h"
 #include "cc/base/cc_export.h"
 #include "cc/base/swap_promise_monitor.h"
 #include "cc/input/scrollbar.h"
 
 namespace gfx {
 class Point;
 class PointF;
 class Vector2d;
 class Vector2dF;
 }
 
 namespace ui { struct LatencyInfo; }
 
 namespace cc {
 
 class LayerScrollOffsetDelegate;
+class ScrollElasticityControllerClient;
 
 class CC_EXPORT InputHandlerClient {
  public:
   virtual ~InputHandlerClient() {}
 
   virtual void WillShutdown() = 0;
   virtual void Animate(base::TimeTicks time) = 0;
   virtual void MainThreadHasStoppedFlinging() = 0;
 
   // Called when scroll deltas reaching the root scrolling layer go unused.
@@ skipping 97 matching lines @@
   virtual bool HaveTouchEventHandlersAt(const gfx::Point& viewport_point) = 0;
 
   // Calling CreateLatencyInfoSwapPromiseMonitor() to get a scoped
   // LatencyInfoSwapPromiseMonitor. During the life time of the
   // LatencyInfoSwapPromiseMonitor, if SetNeedsRedraw() or SetNeedsRedrawRect()
   // is called on LayerTreeHostImpl, the original latency info will be turned
   // into a LatencyInfoSwapPromise.
   virtual scoped_ptr<SwapPromiseMonitor> CreateLatencyInfoSwapPromiseMonitor(
       ui::LatencyInfo* latency) = 0;
 
+  virtual ScrollElasticityControllerClient*
+      GetScrollElasticityControllerClient() = 0;
+
  protected:
   InputHandler() {}
   virtual ~InputHandler() {}
 
  private:
   DISALLOW_COPY_AND_ASSIGN(InputHandler);
 };
 
 }  // namespace cc
 
 #endif  // CC_INPUT_INPUT_HANDLER_H_