[SyncFS] Replace leveldb classes with LevelDBWrapper

chrome/browser/sync_file_system/drive_backend/leveldb_wrapper.cc

 // Copyright 2014 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.
 
 #include "chrome/browser/sync_file_system/drive_backend/leveldb_wrapper.h"
 
 #include <map>
 #include <set>
 #include <string>
 
@@ skipping 175 matching lines @@
   if (status.ok())
     Clear();
 
   return status;
 }
 
 void LevelDBWrapper::Clear() {
   pending_.clear();
 }
 
-leveldb::DB* LevelDBWrapper::GetLevelDBForTesting() {
+leveldb::DB* LevelDBWrapper::GetLevelDB() {
   return db_.get();
 }
 
 }  // namespace drive_backend
 }  // namespace sync_file_system