Remove GestureEvent interface, and rename GestureEventImpl to GestureEvent.

ash/wm/user_activity_detector.cc

 // 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.
 
 #include "ash/wm/user_activity_detector.h"
 
 #include "ash/wm/property_util.h"
 #include "ash/wm/user_activity_observer.h"
 #include "ash/wm/window_util.h"
 #include "ui/aura/window.h"
@@ skipping 40 matching lines @@
     aura::Window* target,
     ui::TouchEvent* event) {
   if (!GetRootWindowController(target->GetRootWindow()))
     return ui::TOUCH_STATUS_END;
   MaybeNotify();
   return ui::TOUCH_STATUS_UNKNOWN;
 }
 
 ui::GestureStatus UserActivityDetector::PreHandleGestureEvent(
     aura::Window* target,
-    ui::GestureEventImpl* event) {
+    ui::GestureEvent* event) {
   if (!GetRootWindowController(target->GetRootWindow()))
     return ui::GESTURE_STATUS_CONSUMED;
   MaybeNotify();
   return ui::GESTURE_STATUS_UNKNOWN;
 }
 
 void UserActivityDetector::MaybeNotify() {
   base::TimeTicks now =
       !now_for_test_.is_null() ? now_for_test_ : base::TimeTicks::Now();
   if (last_observer_notification_time_.is_null() ||
       (now - last_observer_notification_time_).InSecondsF() >=
       kNotifyIntervalSec) {
     FOR_EACH_OBSERVER(UserActivityObserver, observers_, OnUserActivity());
     last_observer_notification_time_ = now;
   }
 }
 
 }  // namespace ash