Refactor sync-specific parts out of SyncNotifier/SyncNotifierObserver

sync/notifier/object_id_payload_map.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_NOTIFIER_OBJECT_ID_PAYLOAD_MAP_H_
+#define SYNC_NOTIFIER_OBJECT_ID_PAYLOAD_MAP_H_
+
+#include <map>
+#include <string>
+
+#include "google/cacheinvalidation/include/types.h"
+#include "sync/notifier/invalidation_util.h"
+
+namespace syncer {
+
+typedef std::map<invalidation::ObjectId,
+                 std::string,
+                 ObjectIdLessThan> ObjectIdPayloadMap;
+
+}  // namespace syncer
+
+#endif  // HOME_DCHENG_SRC_CHROMIUM_SRC_SYNC_NOTIFIER_OBJECT_ID_PAYLOAD_MAP_H_