Hook ScrollElasticityController to InputHandlerProxy

content/renderer/input/input_handler_proxy.h

Index: content/renderer/input/input_handler_proxy.h
diff --git a/content/renderer/input/input_handler_proxy.h b/content/renderer/input/input_handler_proxy.h
index d3b591116c984ac0a1951ca11b3cfaeaf9b0f97c..ab3b109a1699e26eec7bb6d5c747f82c3462703b 100644
--- a/content/renderer/input/input_handler_proxy.h
+++ b/content/renderer/input/input_handler_proxy.h
@@ -19,6 +19,7 @@
 namespace content {
 
 class InputHandlerProxyClient;
+class InputScrollElasticityController;
 
 // This class is a proxy between the content input event filtering and the
 // compositor's input handling logic. InputHandlerProxy instances live entirely
@@ -134,6 +135,9 @@ class CONTENT_EXPORT InputHandlerProxy
   // Non-zero only within the scope of |scrollBy|.
   gfx::Vector2dF current_fling_velocity_;
 
+  // Used to animate rubber-band over-scroll effect on Mac.
+  scoped_ptr<InputScrollElasticityController> scroll_elasticity_controller_;
+
   bool smooth_scroll_enabled_;
 
   DISALLOW_COPY_AND_ASSIGN(InputHandlerProxy);