nt, but if FMP is not
   * available, First Contentful Paint or domContentLoadedEnd may be used as an
   * approximation.
   * @param {number} searchEnd - The right boundary for our search for quiet
   * window. This is either the start of next navigationStart request, or end of
   * traces.
   * @param {number} domContentLoadedEnd - Timestamp of domContentLoadedEnd
   * event for the main loading frame.
   * @param {Array.<!tr.model.TimedEvent>} longTasks - Main thread tasks longer
   * than 50ms overlappi