Refactor ModelTypePayloadMap and ObjectIdPayloadMap to StateMaps.

sync/notifier/object_id_state_map.h

Index: sync/notifier/object_id_state_map.h
diff --git a/sync/notifier/object_id_state_map.h b/sync/notifier/object_id_state_map.h
new file mode 100644
index 0000000000000000000000000000000000000000..17f8cebe686fc31b35e9cc35b7075b479c38ffba
--- /dev/null
+++ b/sync/notifier/object_id_state_map.h
@@ -0,0 +1,35 @@
+// 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_STATE_MAP_H_
+#define SYNC_NOTIFIER_OBJECT_ID_STATE_MAP_H_
+
+#include <map>
+#include <string>
+
+#include "google/cacheinvalidation/include/types.h"
+#include "sync/internal_api/public/base/invalidation_state.h"
+#include "sync/internal_api/public/base/model_type_state_map.h"
+#include "sync/notifier/invalidation_util.h"
+
+namespace syncer {
+
+typedef std::map<invalidation::ObjectId,
+                 InvalidationState,
+                 ObjectIdLessThan> ObjectIdStateMap;
+
+// Converts between ObjectIdStateMaps and ObjectIdSets.
+ObjectIdSet ObjectIdStateMapToSet(const ObjectIdStateMap& id_payloads);
+ObjectIdStateMap ObjectIdSetToStateMap(const ObjectIdSet& ids,
+                                       const std::string& payload);
+
+// Converts between ObjectIdStateMaps and ModelTypeStateMaps.
+ModelTypeStateMap ObjectIdStateMapToModelTypeStateMap(
+    const ObjectIdStateMap& id_payloads);
+ObjectIdStateMap ModelTypeStateMapToObjectIdStateMap(
+    const ModelTypeStateMap& type_payloads);
+
+}  // namespace syncer
+
+#endif  // HOME_DCHENG_SRC_CHROMIUM_SRC_SYNC_NOTIFIER_OBJECT_ID_STATE_MAP_H_