  return tr.b.getAsync(url).then(cb);
  }

  function createViewFromTraces(filenames, traces) {
    const createViewFromTracesTimer = tr.b.Timing.mark(
        'TraceImport', 'createViewFromTraces');
    const m = new tr.Model();

    const trackDetailedModelStatsEl = tr.ui.b.findDeepElementMatching(
        document.body, '#track-detailed-model-stats');
    const importOptions = new tr.importer.ImportOptions();
    importOptions.trackDetailedModelStats = trackDetailedModelStatsEl.checked;
    const i = new