function historyRecordingService (hrService) {
  return hrService || new HistoryRecordingService(svgCanvas.undoMgr)
}
Get a HistoryRecordingService.
@param {module:history.HistoryRecordingService} [hrService] - if exists, return it instead of creating a new service.
@returns {module:history.HistoryRecordingService}