background-paint-into-scrolling-contents-layer-with-root-layer-scrolls-offset.html

<!DOCTYPE html>
<style>
  body {
    height: 10000px;
    margin: 0;
  }
  p {
    position: fixed;
  }
</style>

<body>
  <p>This test verifies document backgrounds are painted at correct
  location when scroll offset is present.</p>
</body>

<script>
window.scrollTo(0, 100);
document.body.style.background = "url('../../images/resources/gracehopper.png')";
</script>

chromium/third_party/blink/web_tests/paint/overflow/background-paint-into-scrolling-contents-layer-with-root-layer-scrolls-offset.html