<!DOCTYPE HTML>
<meta charset=utf-8>
<title>Largest Contentful Paint: repeated image.</title>
<style>
  #image_id {
    width: 10px;
    height: 10px;
  }
</style>
<body>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="resources/largest-contentful-paint-helpers.js"></script>
<script>
  setup({"hide_test_state": true});
  async_test(function (t) {
    assert_implements(window.LargestContentfulPaint, "LargestContentfulPaint is not implemented");
    let beforeLoad = performance.now();
    let firstCallback = true;
    const url = window.location.origin + '/images/black-rectangle.png';
    const observer = new PerformanceObserver(
      t.step_func(entryList => {
        assert_equals(entryList.getEntries().length, 1);
        const entry = entryList.getEntries()[0];

        // First image is shrunk to be 10 x 10. The second image is added at its natural size: 100 x 50.
        const size = firstCallback ? 10 * 10 : 100 * 50;
        const id = firstCallback ? 'image_id' : 'second_id';
        checkImage(entry, url, id, size, beforeLoad);
        if (firstCallback) {
          const img = document.createElement('img');
          img.src = '/images/black-rectangle.png';
          img.id = 'second_id';
          beforeLoad = performance.now();
          document.getElementById('image_div').appendChild(img);
          firstCallback = false;
          return;
        } else {
          t.done();
        }
      })
    );
    observer.observe({type: 'largest-contentful-paint', buffered: true});
  }, 'Repeated image produces different timestamps.');
</script>
<img src='/images/black-rectangle.png' id='image_id'/>
<div id='image_div'></div>
</body>
