message: Disable wait timeout for TPUEstimator.
  If the main loop triggers an error, this will raise immediately.  Fixes testing timeouts.
diff: @@ -101,7 +101,7 @@ class ErrorRendezvous(object):
  except Exception as e: # pylint: disable=broad-except
  self.record_error(source, e, session)
  - def raise_errors(self, timeout_sec=5):
  + def raise_errors(self, timeout_sec=0):
  """Wait for up to `timeout` seconds for all error sources to finish.
  Preferentially raise "interesting" errors (errors not in the
  