Remove #pragma once from chrome/browser/sync

chrome/browser/sync/glue/chrome_extensions_activity_monitor.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_SYNC_GLUE_CHROME_EXTENSIONS_ACTIVITY_MONITOR_H_
 #define CHROME_BROWSER_SYNC_GLUE_CHROME_EXTENSIONS_ACTIVITY_MONITOR_H_
-#pragma once
 
 #include "base/compiler_specific.h"
 #include "base/synchronization/lock.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
 #include "sync/util/extensions_activity_monitor.h"
 
 namespace browser_sync {
 
 // Chrome-specific implementation of syncer::ExtensionsActivityMonitor.
@@ skipping 21 matching lines @@
   Records records_;
   mutable base::Lock records_lock_;
 
   // Used only on UI loop.
   content::NotificationRegistrar registrar_;
 };
 
 }  // namespace browser_sync
 
 #endif  // CHROME_BROWSER_SYNC_GLUE_CHROME_EXTENSIONS_ACTIVITY_MONITOR_H_