Added Aura notification that relaunch and powerwash is required in case of downgrade.

ash/system/tray/default_system_tray_delegate.cc

 // 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.
 
 #include "ash/system/tray/default_system_tray_delegate.h"
 
 #include <string>
 
 #include "ash/session/session_state_delegate.h"
 #include "ash/shell.h"
@@ skipping 72 matching lines @@
 
 const base::string16 DefaultSystemTrayDelegate::GetSupervisedUserMessage()
     const {
   return base::string16();
 }
 
 bool DefaultSystemTrayDelegate::IsUserSupervised() const {
   return false;
 }
 
-bool DefaultSystemTrayDelegate::SystemShouldUpgrade() const {
+bool DefaultSystemTrayDelegate::SystemShouldUpgrade(UpdateInfo* info) const {
+  if (info) {
+    info->severity = UpdateInfo::UPDATE_NORMAL;
+    info->is_factory_reset_required = false;
+  }
   return true;
 }
 
 base::HourClockType DefaultSystemTrayDelegate::GetHourClockType() const {
   return base::k24HourClock;
 }
 
 void DefaultSystemTrayDelegate::ShowSettings() {
 }
 
@@ skipping 178 matching lines @@
 bool DefaultSystemTrayDelegate::IsSearchKeyMappedToCapsLock() {
   return false;
 }
 
 tray::UserAccountsDelegate* DefaultSystemTrayDelegate::GetUserAccountsDelegate(
     const std::string& user_id) {
   return NULL;
 }
 
 }  // namespace ash