Intorduce PowerButtonObserver API

athena/system/power_button_controller.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 ATHENA_SYSTEM_POWER_BUTTON_CONTROLLER_H_
 #define ATHENA_SYSTEM_POWER_BUTTON_CONTROLLER_H_
 
+#include "athena/input/public/input_manager.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/time/time.h"
 #include "base/timer/timer.h"
-#include "chromeos/dbus/power_manager_client.h"
 
 namespace aura {
 class Window;
 }
 
 namespace views {
 class Widget;
 }
 
 namespace athena {
 
 // Shuts down in response to the power button being pressed.
-class PowerButtonController : public chromeos::PowerManagerClient::Observer {
+class PowerButtonController : public PowerButtonObserver {

[oshima, 2014/10/15 22:28:53]

This class should probably be renamed to something like ShutdownDialog. I'll
create a separate CL for it.

  public:
   explicit PowerButtonController(aura::Window* dialog_container);
   virtual ~PowerButtonController();
 
  private:
   enum State {
     // Releasing the power button sends a suspend request.
     STATE_SUSPEND_ON_RELEASE,
 
     // A warning that the device is about to be shutdown is visible. Releasing
     // the power button does not send a suspend or a shutdown request.
     STATE_SHUTDOWN_WARNING_VISIBLE,
 
     // A D-Bus shutdown request has been sent. Shutdown cannot be canceled.
     STATE_SHUTDOWN_REQUESTED,
 
     STATE_OTHER
   };
 
   // Shows the shutdown warning dialog.
   void ShowShutdownWarningDialog();
 
   // Requests shutdown.
   void Shutdown();
 
-  // chromeos::PowerManagerClient::Observer:
-  virtual void BrightnessChanged(int level, bool user_initiated) override;
-  virtual void PowerButtonEventReceived(
-      bool down,
-      const base::TimeTicks& timestamp) override;
+  // PowerButtonObserver:
+  virtual void OnPowerButtonStateChanged(
+      PowerButtonObserver::State state) override;
 
   // |shutdown_warning_message_|'s parent container.
   aura::Window* warning_message_container_;
 
   // Shows a warning that the device is about to be shutdown.
   scoped_ptr<views::Widget> shutdown_warning_message_;
 
-  // Whether the screen brightness was reduced to 0%.
-  bool brightness_is_zero_;
-
-  // The last time at which the screen brightness was 0%.
-  base::TimeTicks zero_brightness_end_time_;
-
   State state_;
 
   base::OneShotTimer<PowerButtonController> timer_;
 
   DISALLOW_COPY_AND_ASSIGN(PowerButtonController);
 };
 
 }  // namespace athena
 
 #endif  // ATHENA_SYSTEM_POWER_BUTTON_CONTROLLER_H_