def MakeResult(output_api, message, committing, modified_files=None):
  """Makes a gcl result. Makes a PresubmitError result if
  |committing| is True, otherwise makes a PresubmitNotifyResult."""
  if not modified_files:
    modified_files = []
  if committing:
    return output_api.PresubmitError(message, modified_files)
  else:
    return output_api.PresubmitNotifyResult(message, modified_files)