[SyncFS] Wire up MetadataDatabaseIndex to MetadataDatabase

chrome/browser/sync_file_system/drive_backend/drive_backend_util.cc

 // Copyright 2013 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/drive_backend_util.h"
 
 #include "base/file_util.h"
 #include "base/logging.h"
 #include "base/memory/scoped_vector.h"
 #include "base/message_loop/message_loop_proxy.h"
@@ skipping 248 matching lines @@
   if (error == -1)
     return SYNC_STATUS_NETWORK_ERROR;
 
   util::Log(logging::LOG_WARNING,
             FROM_HERE,
             "Got unexpected error: %d",
             static_cast<int>(error));
   return SYNC_STATUS_FAILED;
 }
 
+scoped_ptr<FileTracker> CloneFileTracker(const FileTracker* obj) {
+  if (!obj)
+    return scoped_ptr<FileTracker>();
+  return scoped_ptr<FileTracker>(new FileTracker(*obj));
+}
+
 }  // namespace drive_backend
 }  // namespace sync_file_system