[not for review] sync: Don't use group_restriction from ApplyUpdatesCommand.

sync/engine/model_safe_worker.h

Index: sync/engine/model_safe_worker.h
diff --git a/sync/engine/model_safe_worker.h b/sync/engine/model_safe_worker.h
index ced63d6adab45013ed85db4b7f7d846274c41741..db1b73d56b5e67a907808f5dca522a7fccb2b53c 100644
--- a/sync/engine/model_safe_worker.h
+++ b/sync/engine/model_safe_worker.h
@@ -79,6 +79,12 @@ std::string ModelSafeRoutingInfoToString(
 syncable::ModelTypeSet GetRoutingInfoTypes(
     const ModelSafeRoutingInfo& routing_info);
 
+// Extracts a ModelTypeSet containing all types that map to |group| in
+// |routing_info|.
+syncable::FullModelTypeSet GetModelTypesForGroup(
+    ModelSafeGroup group,
+    const ModelSafeRoutingInfo& routing_info);
+
 ModelSafeGroup GetGroupForModelType(const syncable::ModelType type,
                                     const ModelSafeRoutingInfo& routes);