browser: Fix some presubmit errors.

chrome/browser/scoped_pref_update.h

 // Copyright (c) 2010 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.
 //
 // A helper class that assists preferences in firing notifications when lists
 // are changed.
 
 #ifndef CHROME_BROWSER_SCOPED_PREF_UPDATE_H_
 #define CHROME_BROWSER_SCOPED_PREF_UPDATE_H_
 #pragma once
 
 #include "chrome/browser/pref_service.h"
 
 class ScopedPrefUpdate {
  public:
   ScopedPrefUpdate(PrefService* service, const wchar_t* path);
   ~ScopedPrefUpdate();
 
  private:
   PrefService* service_;
   std::wstring path_;
 };
 
-#endif
+#endif  // CHROME_BROWSER_SCOPED_PREF_UPDATE_H_