<html class="reftest-wait">
<meta name="viewport" content="width=device-width minimum-scale=0.5 initial-scale=1.0">
<style>
  html, body {
    margin: 0;
    width: 100%;
    height: 100%;
    scrollbar-width: none;
  }
  div {
    position: absolute;
  }
  .B {
    width: 200%;
    height: 200%;
    background: green;
  }
  .C {
    width: 100%;
    height: 100%;
    background: white;
  }
</style>
<div class="B"></div>
<div class="C"></div>
<script>
document.addEventListener('MozReftestInvalidate', () => {
  // The page here is twice as large as the ICB.
  // If the layout viewport is sized to the ICB, we have a layout
  // scroll range equal to the ICB size, and the scrollTo() call
  // below will bring a green area into view.
  // If the layout viewport is expanded to the whole page, we
  // have an empty layout scroll range, and the scrollTo() call
  // below will have no effect.
  window.scrollTo(window.scrollMaxX, window.scrollMaxY);
  document.documentElement.classList.remove('reftest-wait');
});
</script>
</html>