Merge duplicate code in invalidation helper.

sync/tools/invalidation_helper.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 "sync/tools/invalidation_helper.h"
-
-#include "google/cacheinvalidation/types.pb.h"
-
-namespace syncer {
-
-bool RealModelTypeToObjectId(ModelType model_type,
-                             invalidation::ObjectId* object_id) {
-  std::string notification_type;
-  if (!RealModelTypeToNotificationType(model_type, &notification_type)) {
-    return false;
-  }
-  object_id->Init(ipc::invalidation::ObjectSource::CHROME_SYNC,
-                  notification_type);
-  return true;
-}
-
-ObjectIdSet ModelTypeSetToObjectIdSet(ModelTypeSet model_types) {
-  ObjectIdSet ids;
-  for (ModelTypeSet::Iterator it = model_types.First(); it.Good(); it.Inc()) {
-    invalidation::ObjectId model_type_as_id;
-    if (!RealModelTypeToObjectId(it.Get(), &model_type_as_id)) {
-      DLOG(WARNING) << "Invalid model type " << it.Get();
-      continue;
-    }
-    ids.insert(model_type_as_id);
-  }
-  return ids;
-}
-
-}  // namespace syncer