<!doctype html>
<meta charset=utf-8>
<title></title>
<link rel=match href=hypothetical-box-scroll-viewport-ref.html>
<link rel="help"
      href="https://www.w3.org/TR/CSS2/visudet.html#abs-non-replaced-width">
<div style="position: absolute">Original text</div>
<div style="width: 200vw; height: 10px"></div>
<script>
  // Scroll the viewport.
  window.scrollTo(window.innerWidth * 2, 0);

  // Now force relayout of the abs pos div.
  document.querySelector("div").textContent = "Modified text";
</script>