Make it possible for the scroll offset delegate to intercept fling.

content/port/browser/render_widget_host_view_port.h

 // Copyright (c) 2012 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_PORT_BROWSER_RENDER_WIDGET_HOST_VIEW_PORT_H_
 #define CONTENT_PORT_BROWSER_RENDER_WIDGET_HOST_VIEW_PORT_H_
 
 #include "base/callback.h"
 #include "base/process/kill.h"
 #include "base/strings/string16.h"
@@ skipping 265 matching lines @@
   // Called when a mousewheel event was not processed by the renderer.
   virtual void UnhandledWheelEvent(const WebKit::WebMouseWheelEvent& event) = 0;
 
   // Called prior to forwarding input event messages to the renderer, giving
   // the view a chance to perform in-process event filtering or processing.
   // Return values of |NOT_CONSUMED| or |UNKNOWN| will result in |input_event|
   // being forwarded.
   virtual InputEventAckState FilterInputEvent(
       const WebKit::WebInputEvent& input_event) = 0;
 
-  virtual void GestureEventAck(int gesture_event_type) = 0;
+  virtual void GestureEventAck(int gesture_event_type,
+                               InputEventAckState ack_result) = 0;
 
   virtual void OnOverscrolled(gfx::Vector2dF accumulated_overscroll,
                               gfx::Vector2dF current_fling_velocity) = 0;
 
   virtual void SetPopupType(WebKit::WebPopupType popup_type) = 0;
   virtual WebKit::WebPopupType GetPopupType() = 0;
 
   virtual BrowserAccessibilityManager*
       GetBrowserAccessibilityManager() const = 0;
   virtual void OnAccessibilityNotifications(
@@ skipping 30 matching lines @@
 
 #if defined(OS_WIN) && defined(USE_AURA)
   virtual void SetParentNativeViewAccessible(
       gfx::NativeViewAccessible accessible_parent) = 0;
 #endif
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PORT_BROWSER_RENDER_WIDGET_HOST_VIEW_PORT_H_