Add relaunch prompt to linux help page.

chrome/browser/ui/webui/help/version_updater_unimplemented.h

-// 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.
-
-#ifndef CHROME_BROWSER_UI_WEBUI_HELP_VERSION_UPDATER_UNIMPLEMENTED_H_
-#define CHROME_BROWSER_UI_WEBUI_HELP_VERSION_UPDATER_UNIMPLEMENTED_H_
-#pragma once
-
-#include "base/compiler_specific.h"
-#include "chrome/browser/ui/webui/help/version_updater.h"
-
-// Temporary empty implementation used by platforms that have not specialized
-// VersionUpdater.
-class VersionUpdaterUnimplemented : public VersionUpdater {
- public:
-  // VersionUpdater implementation.
-  virtual void CheckForUpdate(const StatusCallback& callback) OVERRIDE {}
-  virtual void RelaunchBrowser() const OVERRIDE {}
-
- protected:
-  friend class VersionUpdater;
-
-  // Clients must use VersionUpdater::Create().
-  VersionUpdaterUnimplemented() {}
-  virtual ~VersionUpdaterUnimplemented() {}
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(VersionUpdaterUnimplemented);
-};
-
-#endif  // CHROME_BROWSER_UI_WEBUI_HELP_VERSION_UPDATER_UNIMPLEMENTED_H_