// Copyright 2020 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef COMPONENTS_SYNC_MODEL_EMPTY_METADATA_CHANGE_LIST_H_
#define COMPONENTS_SYNC_MODEL_EMPTY_METADATA_CHANGE_LIST_H_

#include <string>

#include "components/sync/model/metadata_change_list.h"

namespace syncer {

// A MetadataChangeList class that does not store anything.
class EmptyMetadataChangeList : public MetadataChangeList {
 public:
  EmptyMetadataChangeList();
  ~EmptyMetadataChangeList() override;

  // MetadataChangeList implementation.
  void UpdateDataTypeState(
      const sync_pb::DataTypeState& data_type_state) override;
  void ClearDataTypeState() override;
  void UpdateMetadata(const std::string& storage_key,
                      const sync_pb::EntityMetadata& metadata) override;
  void ClearMetadata(const std::string& storage_key) override;
  void TransferChangesTo(MetadataChangeList* other) override;
  void DropAllChanges() override;
};

}  // namespace syncer

#endif  // COMPONENTS_SYNC_MODEL_EMPTY_METADATA_CHANGE_LIST_H_