chromeos: Migrate SignOut and RequestRestartForUpdate to mojo interface

ash/common/system/tray/system_tray_delegate.h

 // 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.
 
 #ifndef ASH_COMMON_SYSTEM_TRAY_SYSTEM_TRAY_DELEGATE_H_
 #define ASH_COMMON_SYSTEM_TRAY_SYSTEM_TRAY_DELEGATE_H_
 
 #include <memory>
 #include <string>
 #include <vector>
@@ skipping 124 matching lines @@
 
   // Returns true if notification tray should appear.
   virtual bool ShouldShowNotificationTray() const;
 
   // Shows information about enterprise enrolled devices.
   virtual void ShowEnterpriseInfo();
 
   // Shows login UI to add other users to this session.
   virtual void ShowUserLogin();
 
-  // Attempts to sign out the user.
-  virtual void SignOut();
-
-  // Attempts to restart the system for update.
-  virtual void RequestRestartForUpdate();
-
   // Returns a list of available bluetooth devices.
   virtual void GetAvailableBluetoothDevices(BluetoothDeviceList* devices);
 
   // Requests bluetooth start discovering devices.
   virtual void BluetoothStartDiscovering();
 
   // Requests bluetooth stop discovering devices.
   virtual void BluetoothStopDiscovering();
 
   // Connect to a specific bluetooth device.
@@ skipping 68 matching lines @@
   // Creates a system tray item for display rotation lock.
   // TODO(jamescook): Remove this when mus has support for display management
   // and we have a DisplayManager equivalent. See http://crbug.com/548429
   virtual std::unique_ptr<SystemTrayItem> CreateRotationLockTrayItem(
       SystemTray* tray);
 };
 
 }  // namespace ash
 
 #endif  // ASH_COMMON_SYSTEM_TRAY_SYSTEM_TRAY_DELEGATE_H_