PASS destroyed context
-PASS caught expected exception "NotSupportedError: Failed to execute 'registerElement' on 'Document': Registration failed for type 'x-a'. The context is no longer valid."
+PASS caught expected exception "InvalidStateError: Failed to execute 'registerElement' on 'Document': Registration failed for type 'x-a'. The context is no longer valid."
PASS child done
PASS successfullyParsed is true