chromeos: Migrate SignOut and RequestRestartForUpdate to mojo interface

ash/common/system/tray/system_tray_delegate.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 "ash/common/system/tray/system_tray_delegate.h"
 
 #include "ash/common/system/tray/ime_info.h"
 #include "ash/common/system/tray/system_tray_item.h"
 
 namespace ash {
@@ skipping 66 matching lines @@
 }
 
 bool SystemTrayDelegate::ShouldShowNotificationTray() const {
   return false;
 }
 
 void SystemTrayDelegate::ShowEnterpriseInfo() {}
 
 void SystemTrayDelegate::ShowUserLogin() {}
 
-void SystemTrayDelegate::SignOut() {}
-
-void SystemTrayDelegate::RequestRestartForUpdate() {}
-
 void SystemTrayDelegate::GetAvailableBluetoothDevices(
     BluetoothDeviceList* list) {}
 
 void SystemTrayDelegate::BluetoothStartDiscovering() {}
 
 void SystemTrayDelegate::BluetoothStopDiscovering() {}
 
 void SystemTrayDelegate::ConnectToBluetoothDevice(const std::string& address) {}
 
 void SystemTrayDelegate::GetCurrentIME(IMEInfo* info) {}
@@ skipping 64 matching lines @@
 VPNDelegate* SystemTrayDelegate::GetVPNDelegate() const {
   return nullptr;
 }
 
 std::unique_ptr<SystemTrayItem> SystemTrayDelegate::CreateRotationLockTrayItem(
     SystemTray* tray) {
   return nullptr;
 }
 
 }  // namespace ash