<!DOCTYPE HTML>
<meta charset=utf-8>
<title>Largest Contentful Paint: src change triggers new entry.</title>
<body>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="resources/largest-contentful-paint-helpers.js"></script>
<img src='/images/lcp-1x1.png' id='image_id' width="133" height="106"/>
<script>
  async_test(function (t) {
    assert_implements(window.LargestContentfulPaint, "LargestContentfulPaint is not implemented");
    let befo