Replace more ObserverList with base::ObserverList.

ui/base/user_activity/user_activity_detector.h

 // Copyright 2014 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_BASE_USER_ACTIVITY_USER_ACTIVITY_DETECTOR_H_
 #define UI_BASE_USER_ACTIVITY_USER_ACTIVITY_DETECTOR_H_
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/observer_list.h"
@@ skipping 44 matching lines @@
   base::TimeTicks GetCurrentTime() const;
 
   // Processes the event after it has been converted from a PlatformEvent.
   void ProcessReceivedEvent(const ui::Event* event);
 
   // Updates |last_activity_time_|.  Additionally notifies observers and
   // updates |last_observer_notification_time_| if enough time has passed
   // since the last notification.
   void HandleActivity(const ui::Event* event);
 
-  ObserverList<UserActivityObserver> observers_;
+  base::ObserverList<UserActivityObserver> observers_;
 
   // Last time at which user activity was observed.
   base::TimeTicks last_activity_time_;
 
   // Last time at which we notified observers that the user was active.
   base::TimeTicks last_observer_notification_time_;
 
   // If set, used when the current time is needed.  This can be set by tests to
   // simulate the passage of time.
   base::TimeTicks now_for_test_;
 
   // If set, mouse events will be ignored until this time is reached. This
   // is to avoid reporting mouse events that occur when displays are turned
   // on or off as user activity.
   base::TimeTicks honor_mouse_events_time_;
 
   DISALLOW_COPY_AND_ASSIGN(UserActivityDetector);
 };
 
 }  // namespace ui
 
 #endif  // UI_BASE_USER_ACTIVITY_USER_ACTIVITY_DETECTOR_H_