Re-write many calls to WrapUnique() with MakeUnique()

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>
 #include <utility>
@@ skipping 163 matching lines @@
       *value = transaction.second;
       return leveldb::Status();
     case DELETE_OPERATION:
       return leveldb::Status::NotFound(leveldb::Slice());
   }
   NOTREACHED();
   return leveldb::Status::NotSupported("Not supported operation.");
 }
 
 std::unique_ptr<LevelDBWrapper::Iterator> LevelDBWrapper::NewIterator() {
-  return base::WrapUnique(new Iterator(this));
+  return base::MakeUnique<Iterator>(this);
 }
 
 leveldb::Status LevelDBWrapper::Commit() {
   leveldb::WriteBatch batch;
   for (PendingOperationMap::iterator itr = pending_.begin();
        itr != pending_.end(); ++itr) {
     const leveldb::Slice key(itr->first);
     const Transaction& transaction = itr->second;
     switch (transaction.first) {
       case PUT_OPERATION:
@@ skipping 18 matching lines @@
   num_puts_ = 0;
   num_deletes_ = 0;
 }
 
 leveldb::DB* LevelDBWrapper::GetLevelDB() {
   return db_.get();
 }
 
 }  // namespace drive_backend
 }  // namespace sync_file_system