Add relaunch prompt to linux help page.

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