Move DisplayChangeObserver + tests from ash to ui.

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/compiler_specific.h"
 #include "base/macros.h"
 #include "base/observer_list.h"
@@ skipping 15 matching lines @@
   // Amount of time that mouse events should be ignored after notification
   // is received that displays' power states are being changed.
   static const int kDisplayPowerChangeIgnoreMouseMs;
 
   UserActivityDetector();
   ~UserActivityDetector() override;
 
   // Returns the UserActivityDetector instance if one was created.
   static UserActivityDetector* Get();
 
+  // Calls OnDisplayPowerChanging() on instance if one was created.
+  static void OnDisplayPowerChangingStatic();

[sadrul, 2016/11/29 18:24:40]

Do we need 'Static'?

[kylechar, 2016/11/30 22:53:31]

A change in a parent CL has made this unnecessary regardless.

+
   base::TimeTicks last_activity_time() const { return last_activity_time_; }
   std::string last_activity_name() const { return last_activity_name_; }
 
   void set_now_for_test(base::TimeTicks now) { now_for_test_ = now; }
 
   bool HasObserver(const UserActivityObserver* observer) const;
   void AddObserver(UserActivityObserver* observer);
   void RemoveObserver(UserActivityObserver* observer);
 
   // Called when displays are about to be turned on or off.
@@ skipping 36 matching lines @@
   // 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_