bserverPromise = new Promise(resolve => {
    const observer = new PerformanceObserver(
      entryList => {
        resolve(entryList);
      }
    ).observe({ entryTypes: ['layout-shift'] });
  });

  // User input event
  await clickAndBlockMain('button');

  // Modify the position of the div to trigger layout shift.
  document.getElementById('myDiv').style = "top: 60px";

  const layoutShiftEntryList = await observerPromise;
  const endTime = performance.now();

  assert_equals(layoutShiftEntryList.getE