Remove #pragma once from chrome/browser/extensions

chrome/browser/extensions/api/alarms/alarm_manager.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_API_ALARMS_ALARM_MANAGER_H__
 #define CHROME_BROWSER_EXTENSIONS_API_ALARMS_ALARM_MANAGER_H__
-#pragma once
 
 #include <string>
 #include <map>
 #include <vector>
 
 #include "base/memory/weak_ptr.h"
 #include "base/timer.h"
 #include "chrome/browser/extensions/extension_function.h"
 #include "chrome/common/extensions/api/alarms.h"
 #include "content/public/browser/notification_observer.h"
@@ skipping 131 matching lines @@
   AlarmMap alarms_;
 
   // The previous and next time that alarms were and will be run.
   base::Time last_poll_time_;
   base::Time next_poll_time_;
 };
 
 } //  namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_API_ALARMS_ALARM_MANAGER_H__