chromeos: Simplify ShutdownPolicyHandler

chrome/browser/ui/ash/system_tray_delegate_chromeos.h

 // Copyright 2013 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 CHROME_BROWSER_UI_ASH_SYSTEM_TRAY_DELEGATE_CHROMEOS_H_
 #define CHROME_BROWSER_UI_ASH_SYSTEM_TRAY_DELEGATE_CHROMEOS_H_
 
 #include <stdint.h>
 
 #include <string>
@@ skipping 105 matching lines @@
   void ActiveUserWasChanged() override;
   bool IsSearchKeyMappedToCapsLock() override;
   void AddCustodianInfoTrayObserver(
       ash::CustodianInfoTrayObserver* observer) override;
   void RemoveCustodianInfoTrayObserver(
       ash::CustodianInfoTrayObserver* observer) override;
   void AddShutdownPolicyObserver(
       ash::ShutdownPolicyObserver* observer) override;
   void RemoveShutdownPolicyObserver(
       ash::ShutdownPolicyObserver* observer) override;
-  void ShouldRebootOnShutdown(
-      const ash::RebootOnShutdownCallback& callback) override;
+  void CheckIfRebootOnShutdown() override;
   ash::VPNDelegate* GetVPNDelegate() const override;
   std::unique_ptr<ash::SystemTrayItem> CreateRotationLockTrayItem(
       ash::SystemTray* tray) override;
 
   // Overridden from user_manager::UserManager::UserSessionStateObserver:
   void UserAddedToSession(const user_manager::User* active_user) override;
   void ActiveUserChanged(const user_manager::User* active_user) override;
 
   void UserChangedChildStatus(user_manager::User* user) override;
 
@@ skipping 137 matching lines @@
 
   base::WeakPtrFactory<SystemTrayDelegateChromeOS> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(SystemTrayDelegateChromeOS);
 };
 
 ash::SystemTrayDelegate* CreateSystemTrayDelegate();
 
 }  // namespace chromeos
 #endif  // CHROME_BROWSER_UI_ASH_SYSTEM_TRAY_DELEGATE_CHROMEOS_H_