Remove #pragma once from sync

sync/notifier/invalidation_notifier.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.
 //
 // An implementation of SyncNotifier that wraps an invalidation
 // client.  Handles the details of connecting to XMPP and hooking it
 // up to the invalidation client.
 //
 // You probably don't want to use this directly; use
 // NonBlockingInvalidationNotifier.
 
 #ifndef SYNC_NOTIFIER_INVALIDATION_NOTIFIER_H_
 #define SYNC_NOTIFIER_INVALIDATION_NOTIFIER_H_
-#pragma once
 
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/observer_list.h"
 #include "base/threading/non_thread_safe.h"
 #include "sync/internal_api/public/base/model_type.h"
 #include "sync/internal_api/public/util/weak_handle.h"
@@ skipping 77 matching lines @@
 
   // The invalidation client.
   ChromeInvalidationClient invalidation_client_;
 
   DISALLOW_COPY_AND_ASSIGN(InvalidationNotifier);
 };
 
 }  // namespace syncer
 
 #endif  // SYNC_NOTIFIER_INVALIDATION_NOTIFIER_H_