[Sync] Rename csync namespace to syncer

sync/internal_api/public/syncable/model_type_payload_map.h

Index: sync/internal_api/public/syncable/model_type_payload_map.h
diff --git a/sync/internal_api/public/syncable/model_type_payload_map.h b/sync/internal_api/public/syncable/model_type_payload_map.h
index 8f3319a340e395e69f7ed39ab384f17b409b7e3e..5ea9919195d170d036d3c50a123ed65a1be49a03 100644
--- a/sync/internal_api/public/syncable/model_type_payload_map.h
+++ b/sync/internal_api/public/syncable/model_type_payload_map.h
@@ -37,7 +37,7 @@ ModelTypeSet ModelTypePayloadMapToEnumSet(
 // Make a TypePayloadMap for all the enabled types in a
 // ModelSafeRoutingInfo using a default payload.
 ModelTypePayloadMap ModelTypePayloadMapFromRoutingInfo(
-    const csync::ModelSafeRoutingInfo& routes,
+    const syncer::ModelSafeRoutingInfo& routes,
     const std::string& payload);
 
 std::string ModelTypePayloadMapToString(
@@ -53,7 +53,7 @@ void CoalescePayloads(ModelTypePayloadMap* original,
                       const ModelTypePayloadMap& update);
 
 void PurgeStalePayload(ModelTypePayloadMap* original,
-                       const csync::ModelSafeRoutingInfo& routing_info);
+                       const syncer::ModelSafeRoutingInfo& routing_info);
 
 }  // namespace syncable