Intorduce PowerButtonObserver API

athena/system/shutdown_dialog.h

Index: athena/system/shutdown_dialog.h
diff --git a/athena/system/power_button_controller.h b/athena/system/shutdown_dialog.h
similarity index 57%
rename from athena/system/power_button_controller.h
rename to athena/system/shutdown_dialog.h
index b1540b9e38170bc5f3c1a750e00984e567f6413f..bda5adda8ab0c070bf2526736d3be4ea0fa7e5f4 100644
--- a/athena/system/power_button_controller.h
+++ b/athena/system/shutdown_dialog.h
@@ -2,13 +2,13 @@
 // 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_
+#ifndef ATHENA_SYSTEM_SHUTDOWN_DIALOG_H_
+#define ATHENA_SYSTEM_SHUTDOWN_DIALOG_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;
@@ -21,10 +21,10 @@ class Widget;
 namespace athena {
 
 // Shuts down in response to the power button being pressed.
-class PowerButtonController : public chromeos::PowerManagerClient::Observer {
+class ShutdownDialog : public PowerButtonObserver {
  public:
-  explicit PowerButtonController(aura::Window* dialog_container);
-  virtual ~PowerButtonController();
+  explicit ShutdownDialog(aura::Window* dialog_container);
+  virtual ~ShutdownDialog();
 
  private:
   enum State {
@@ -47,11 +47,9 @@ class PowerButtonController : public chromeos::PowerManagerClient::Observer {
   // 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_;
@@ -59,19 +57,13 @@ class PowerButtonController : public chromeos::PowerManagerClient::Observer {
   // 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_;
+  base::OneShotTimer<ShutdownDialog> timer_;
 
-  DISALLOW_COPY_AND_ASSIGN(PowerButtonController);
+  DISALLOW_COPY_AND_ASSIGN(ShutdownDialog);
 };
 
 }  // namespace athena
 
-#endif  // ATHENA_SYSTEM_POWER_BUTTON_CONTROLLER_H_
+#endif  // ATHENA_SYSTEM_SHUTDOWN_DIALOG_H_