Remove #pragma once from chrome/browser/extensions

chrome/browser/extensions/extension_navigation_observer.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_EXTENSIONS_EXTENSION_NAVIGATION_OBSERVER_H_
 #define CHROME_BROWSER_EXTENSIONS_EXTENSION_NAVIGATION_OBSERVER_H_
-#pragma once
 
 #include <set>
 #include <string>
 
 #include "base/memory/scoped_ptr.h"
 #include "chrome/browser/extensions/extension_install_prompt.h"
 #include "content/public/browser/notification_registrar.h"
 
 class Profile;
 
@@ skipping 38 matching lines @@
 
   // The data we keep track of when prompting to enable extensions.
   std::string in_progress_prompt_extension_id_;
   content::NavigationController* in_progress_prompt_navigation_controller_;
 
   // The extension ids we've already prompted the user about.
   std::set<std::string> prompted_extensions_;
 };
 
 #endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_NAVIGATION_OBSERVER_H_