[Sync] Remove backend unrecoverable error handler

sync/internal_api/sync_rollback_manager_base_unittest.cc

Index: sync/internal_api/sync_rollback_manager_base_unittest.cc
diff --git a/sync/internal_api/sync_rollback_manager_base_unittest.cc b/sync/internal_api/sync_rollback_manager_base_unittest.cc
index fd1c12f849d33d086dca50ac2f7aadd1edfad243..bb5ec93f7661a03c97d3cf0d9fb30f7a8ca5d199 100644
--- a/sync/internal_api/sync_rollback_manager_base_unittest.cc
+++ b/sync/internal_api/sync_rollback_manager_base_unittest.cc
@@ -26,7 +26,7 @@ class SyncTestRollbackManager : public SyncRollbackManagerBase {
         args->database_location,
         args->internal_components_factory.get(),
         InternalComponentsFactory::STORAGE_IN_MEMORY,
-        args->unrecoverable_error_handler.Pass(),
+        args->unrecoverable_error_handler,
         args->report_unrecoverable_error_function);
   }
 };