sync: Implement per-type update processing

sync/engine/store_timestamps_command.h

-// Copyright (c) 2012 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.
-
-#ifndef SYNC_ENGINE_STORE_TIMESTAMPS_COMMAND_H_
-#define SYNC_ENGINE_STORE_TIMESTAMPS_COMMAND_H_
-
-#include "base/compiler_specific.h"
-#include "sync/base/sync_export.h"
-#include "sync/engine/syncer_command.h"
-#include "sync/engine/syncer_types.h"
-#include "sync/internal_api/public/base/model_type.h"
-
-namespace sync_pb {
-class GetUpdatesResponse;
-}  // namespace sync_pb
-
-namespace syncer {
-
-namespace syncable {
-class Directory;
-}  // namespace syncable
-
-// Sets |dir|'s progress markers from the data in |response|.  Returns
-// the set of model types with new progress markers.
-SYNC_EXPORT_PRIVATE ModelTypeSet ProcessNewProgressMarkers(
-    const sync_pb::GetUpdatesResponse& response,
-    syncable::Directory* dir);
-
-// A syncer command that extracts the changelog timestamp information from
-// a GetUpdatesResponse (fetched in DownloadUpdatesCommand) and stores
-// it in the directory.  This is meant to run immediately after
-// ProcessUpdatesCommand.
-//
-// Preconditions - all updates in the SyncerSesssion have been stored in the
-//                 database, meaning it is safe to update the persisted
-//                 timestamps.
-//
-// Postconditions - The next_timestamp returned by the server will be
-//                  saved into the directory (where it will be used
-//                  the next time that DownloadUpdatesCommand runs).
-class StoreTimestampsCommand : public SyncerCommand {
- public:
-  StoreTimestampsCommand();
-  virtual ~StoreTimestampsCommand();
-
-  // SyncerCommand implementation.
-  virtual SyncerError ExecuteImpl(sessions::SyncSession* session) OVERRIDE;
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(StoreTimestampsCommand);
-};
-
-}  // namespace syncer
-
-#endif  // SYNC_ENGINE_STORE_TIMESTAMPS_COMMAND_H_