 *
   */
  function* getLoadingIntervals_(model, chromeBounds) {
    const ttiIntervals = getNavigationTTIIntervals_(model);
    for (const ttiInterval of ttiIntervals) {
      yield {
        bounds: ttiInterval,
        name: 'load',
        description: 'page loads',
        perSecond: false
      };
    }
  }

  /**
   * @returns {tr.b.math.Range} The boundaries of the Chrome portion of the
   * trace.
   */
  function computeChromeBounds_(model) {
    const chromeBounds = new tr.b.math.Range();
    con