Remove GestureEvent interface, and rename GestureEventImpl to GestureEvent.

ui/aura/event_filter.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 UI_AURA_EVENT_FILTER_H_
 #define UI_AURA_EVENT_FILTER_H_
 
 #include "base/basictypes.h"
 #include "ui/aura/aura_export.h"
 #include "ui/base/events.h"
 
 namespace ui {
-class GestureEventImpl;
+class GestureEvent;
 class KeyEvent;
 class MouseEvent;
 class TouchEvent;
 }
 
 namespace aura {
 
 class Window;
 
 // An object that filters events sent to an owner window. The filter can stop
@@ skipping 28 matching lines @@
 
   // Returns a value other than ui::TOUCH_STATUS_UNKNOWN if the event is
   // consumed.
   virtual ui::TouchStatus PreHandleTouchEvent(Window* target,
                                               ui::TouchEvent* event) = 0;
 
   // Returns a value other than ui::GESTURE_STATUS_UNKNOWN if the gesture is
   // consumed.
   virtual ui::GestureStatus PreHandleGestureEvent(
       Window* target,
-      ui::GestureEventImpl* event) = 0;
+      ui::GestureEvent* event) = 0;
 };
 
 }  // namespace aura
 
 #endif  // UI_AURA_EVENT_FILTER_H_