Refactor sync-specific parts out of SyncNotifier/SyncNotifierObserver

sync/notifier/object_id_payload_map.cc

+// 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.
+
+#include "sync/notifier/object_id_payload_map.h"
+
+namespace syncer {
+
+ModelTypePayloadMap ObjectIdPayloadMapToModelTypePayloadMap(
+    const ObjectIdPayloadMap& id_payloads) {
+  ModelTypePayloadMap types_with_payloads;
+  for (ObjectIdPayloadMap::const_iterator it = id_payloads.begin();
+       it != id_payloads.end(); ++it) {
+    ModelType model_type;
+    if (!syncer::ObjectIdToRealModelType(it->first, &model_type)) {
+      DLOG(WARNING) << "Invalid object ID: "
+                    << syncer::ObjectIdToString(it->first);
+      continue;
+    }
+    types_with_payloads[model_type] = it->second;
+  }
+  return types_with_payloads;
+}
+
+syncer::ObjectIdPayloadMap ModelTypePayloadMapToObjectIdPayloadMap(
+    const ModelTypePayloadMap& type_payloads) {
+  ObjectIdPayloadMap id_payloads;
+  for (ModelTypePayloadMap::const_iterator it = type_payloads.begin();
+       it != type_payloads.end(); ++it) {
+    invalidation::ObjectId id;
+    if (!RealModelTypeToObjectId(it->first, &id)) {
+      DLOG(WARNING) << "Invalid model type " << it->first;
+      continue;
+    }
+    id_payloads[id] = it->second;
+  }
+  return id_payloads;
+}
+
+}  // namespace syncer