ash: Refresh the tray items, instead of recreating them, when login status changes.

ash/system/bluetooth/tray_bluetooth.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/system/bluetooth/tray_bluetooth.h"
 
 #include "ash/shell.h"
 #include "ash/system/tray/system_tray.h"
 #include "ash/system/tray/system_tray_delegate.h"
 #include "ash/system/tray/tray_constants.h"
@@ skipping 232 matching lines @@
 }
 
 void TrayBluetooth::DestroyDefaultView() {
   default_.reset();
 }
 
 void TrayBluetooth::DestroyDetailedView() {
   detailed_.reset();
 }
 
+void TrayBluetooth::UpdateAfterLoginStatusChange(user::LoginStatus status) {
+}
+
 void TrayBluetooth::OnBluetoothRefresh() {
   BluetoothDeviceList list;
   Shell::GetInstance()->tray_delegate()->GetAvailableBluetoothDevices(&list);
   if (default_.get())
     default_->UpdateLabel();
   if (detailed_.get())
     detailed_->Update(list);
 }
 
 }  // namespace internal
 }  // namespace ash