mash: Move SystemTrayDelegate ownership to WmShell

chrome/browser/chromeos/power/power_button_observer.cc

 // Copyright (c) 2012 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 "chrome/browser/chromeos/power/power_button_observer.h"
 
 #include "ash/common/system/tray/system_tray_delegate.h"
+#include "ash/common/wm_shell.h"
 #include "ash/shell.h"
 #include "ash/system/user/login_status.h"
 #include "ash/wm/power_button_controller.h"
 #include "base/logging.h"
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/chromeos/login/lock/screen_locker.h"
 #include "chrome/browser/chromeos/power/session_state_controller_delegate_chromeos.h"
 #include "chromeos/dbus/dbus_thread_manager.h"
 #include "content/public/browser/notification_service.h"
 
 namespace ash {
 class LockStateControllerDelegate;
 }
 
 namespace chromeos {
 
 namespace {
 
 ash::LoginStatus GetCurrentLoginStatus() {
-  if (!ash::Shell::GetInstance()->system_tray_delegate())
-    return ash::LoginStatus::NOT_LOGGED_IN;
-  return ash::Shell::GetInstance()->system_tray_delegate()->
-      GetUserLoginStatus();
+  if (ash::WmShell::Get()->system_tray_delegate())
+    return ash::WmShell::Get()->system_tray_delegate()->GetUserLoginStatus();
+
+  return ash::LoginStatus::NOT_LOGGED_IN;
 }
 
 }  // namespace
 
 PowerButtonObserver::PowerButtonObserver() {
   // TODO: Remove after resolving crbug.com/452599.
   VLOG(0) << "Creating PowerButtonObserver " << this;
 
   ash::Shell::GetInstance()->lock_state_controller()->SetDelegate(
       std::unique_ptr<ash::LockStateControllerDelegate>(
@@ skipping 55 matching lines @@
   }
 }
 
 void PowerButtonObserver::PowerButtonEventReceived(
     bool down, const base::TimeTicks& timestamp) {
   ash::Shell::GetInstance()->power_button_controller()->
       OnPowerButtonEvent(down, timestamp);
 }
 
 }  // namespace chromeos