Remove #pragma once from sync

sync/test/test_directory_backing_store.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 SYNC_TEST_TEST_DIRECTORY_BACKING_STORE_H_
 #define SYNC_TEST_TEST_DIRECTORY_BACKING_STORE_H_
-#pragma once
 
 #include "base/gtest_prod_util.h"
 #include "sync/syncable/directory_backing_store.h"
 
 namespace syncer {
 namespace syncable {
 
 // This implementation of DirectoryBackingStore does not manage its own
 // database.  This makes it more flexible (and more complex) than the
 // InMemoryDirectoryBackingStore.
@@ skipping 28 matching lines @@
   FRIEND_TEST_ALL_PREFIXES(DirectoryBackingStoreTest, DeleteEntries);
   FRIEND_TEST_ALL_PREFIXES(DirectoryBackingStoreTest, GenerateCacheGUID);
   FRIEND_TEST_ALL_PREFIXES(MigrationTest, ToCurrentVersion);
   friend class MigrationTest;
 };
 
 }  // namespace syncable
 }  // namespace syncer
 
 #endif  // SYNC_TEST_TEST_DIRECTORY_BACKING_STORE_H_