reLoad = performance.now();
    document.getElementById('image_id').src = '/images/lcp-133x106.png';
    const url = window.location.origin + '/images/lcp-133x106.png';
    const observer = new PerformanceObserver(
      t.step_func(function(entryList) {
        let entries = entryList.getEntries().filter(e => e.url === url);
        if (entries.length === 0)
          return;
        assert_equals(entries.length, 1);
        const entry = entries[0];
        const size = 133 * 106;
        checkImage(entry