Clean-up of the system shutdown code paths

ash/system/date/date_default_view.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 "ash/system/date/date_default_view.h"
 
 #include "ash/metrics/user_metrics_recorder.h"
 #include "ash/session/session_state_delegate.h"
 #include "ash/shell.h"
 #include "ash/system/date/date_view.h"
 #include "ash/system/tray/special_popup_row.h"
 #include "ash/system/tray/system_tray_delegate.h"
 #include "ash/system/tray/tray_constants.h"
 #include "ash/system/tray/tray_popup_header_button.h"
+#include "ash/wm/lock_state_controller.h"
 #include "grit/ash_resources.h"
 #include "grit/ash_strings.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/views/border.h"
 #include "ui/views/controls/button/button.h"
 #include "ui/views/layout/fill_layout.h"
 #include "ui/views/view.h"
 
 namespace {
 
@@ skipping 79 matching lines @@
 
 void DateDefaultView::ButtonPressed(views::Button* sender,
                                     const ui::Event& event) {
   ash::Shell* shell = ash::Shell::GetInstance();
   ash::SystemTrayDelegate* tray_delegate = shell->system_tray_delegate();
   if (sender == help_) {
     shell->metrics()->RecordUserMetricsAction(ash::UMA_TRAY_HELP);
     tray_delegate->ShowHelp();
   } else if (sender == shutdown_) {
     shell->metrics()->RecordUserMetricsAction(ash::UMA_TRAY_SHUT_DOWN);
-    tray_delegate->ShutDown();
+    ash::Shell::GetInstance()->lock_state_controller()->RequestShutdown(
+        ash::LockStateController::POWER_OFF);
   } else if (sender == lock_) {
     shell->metrics()->RecordUserMetricsAction(ash::UMA_TRAY_LOCK_SCREEN);
     tray_delegate->RequestLockScreen();
   } else {
     NOTREACHED();
   }
 }
 
 }  // namespace ash