message: Python 3 migration.
diff: @@ -2149,7 +2149,7 @@ class TensorFlowTestCase(googletest.TestCase):
  if isinstance(expected_message_maybe_ascii, type(message)):
  expected_message = expected_message_maybe_ascii
  self._AssertProtoEquals(expected_message, message)
  - elif isinstance(expected_message_maybe_ascii, str):
  + elif isinstance(expected_message_maybe_ascii, (str, bytes)):
  expected_message = type(message)()
  text_format.Merge(
  expected_message_maybe_ascii,
  