ng characteristics:
 * - The unit is ms.
 * - Produces wall-clock-time and CPU-time outcome.
 * - The last incomplete second is curtailed
 */
tr.exportTo('tr.metrics.sh', function() {
  const timeDurationInMs_smallerIsBetter =
      tr.b.Unit.byName.timeDurationInMs_smallerIsBetter;
  const EventFinderUtils = tr.e.chrome.EventFinderUtils;

  const LOADING_METRIC_BOUNDARIES = tr.v.HistogramBinBoundaries
      .createLinear(0, 1e3, 20)  // 50ms step to 1s
      .addLinearBins(3e3, 20) // 100ms step to 3s
    