Cleanup: Remove VersionUpdater::RelaunchBrowser interface method.

chrome/browser/ui/webui/help/version_updater_basic.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 "chrome/browser/ui/webui/help/version_updater_basic.h"
 
 #include "base/strings/string16.h"
-#include "chrome/browser/lifetime/application_lifetime.h"
 #include "chrome/browser/upgrade_detector.h"
 
 void VersionUpdaterBasic::CheckForUpdate(
     const StatusCallback& status_callback,
     const PromoteCallback&) {
   if (UpgradeDetector::GetInstance()->notify_upgrade())
     status_callback.Run(NEARLY_UPDATED, 0, base::string16());
   else
     status_callback.Run(DISABLED, 0, base::string16());
 }
 
-void VersionUpdaterBasic::RelaunchBrowser() const {
-  chrome::AttemptRestart();
-}
-
 VersionUpdater* VersionUpdater::Create(content::WebContents* web_contents) {
   return new VersionUpdaterBasic;
 }