ion of the interval.
   *       Used to generate the metric descriptions.
   *     perSecond {boolean}: Whether metrics over this interval should be
   *       reported as per-second values (e.g. power). If not, integrated values
   *       over the whole interval (e.g. energy) are reported.
   *   }
   *
   */
  function* computeTimeIntervals_(model) {
    const chromeHelper = model.getOrCreateHelper(
        tr.model.helpers.ChromeModelHelper);
    const powerSeries = model.device.powerSeries;
    if (pow