Revert of Intorduce PowerButtonObserver API

athena/system/system_ui_impl.cc

 // 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.
 
 #include "athena/system/public/system_ui.h"
 
 #include "athena/screen/public/screen_manager.h"
 #include "athena/system/background_controller.h"
 #include "athena/system/orientation_controller.h"
-#include "athena/system/shutdown_dialog.h"
+#include "athena/system/power_button_controller.h"
 #include "athena/system/status_icon_container_view.h"
 #include "athena/system/time_view.h"
 #include "athena/util/container_priorities.h"
 #include "athena/util/fill_layout_manager.h"
 #include "base/logging.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "ui/aura/window.h"
 #include "ui/views/view.h"
 
@@ skipping 78 matching lines @@
     system_modal_container_ =
         screen_manager->CreateContainer(system_modal_params);
     login_screen_system_modal_container_ = screen_manager->CreateContainer(
         ScreenManager::ContainerParams("AthenaLoginScreenSystemModalContainer",
                                        CP_LOGIN_SCREEN_SYSTEM_MODAL));
 
     // Use |login_screen_system_modal_container_| for the power button's dialog
     // because it needs to show over the login screen.
     // TODO(pkotwicz): Pick the most appropriate container based on whether the
     // user has logged in.
-    shutdown_dialog_.reset(
-        new ShutdownDialog(login_screen_system_modal_container_));
+    power_button_controller_.reset(
+        new PowerButtonController(login_screen_system_modal_container_));
     background_controller_.reset(
         new BackgroundController(background_container_));
   }
 
   virtual void SetBackgroundImage(const gfx::ImageSkia& image) override {
     background_controller_->SetImage(image);
   }
 
   virtual views::View* CreateSystemInfoView(ColorScheme color_scheme) override {
     return new SystemInfoView(color_scheme, system_modal_container_);
   }
 
  private:
   scoped_ptr<OrientationController> orientation_controller_;
-  scoped_ptr<ShutdownDialog> shutdown_dialog_;
+  scoped_ptr<PowerButtonController> power_button_controller_;
   scoped_ptr<BackgroundController> background_controller_;
 
   // The parent container for the background.
   aura::Window* background_container_;
 
   // The parent container used by system modal dialogs.
   aura::Window* system_modal_container_;
 
   // The parent container used by system modal dialogs when the login screen is
   // visible.
@@ skipping 20 matching lines @@
 }
 
 // static
 void SystemUI::Shutdown() {
   CHECK(instance);
   delete instance;
   instance = NULL;
 }
 
 }  // namespace athena