chromium/third_party/blink/web_tests/fast/scroll-behavior/resources/subframe-with-scroll.html

<!DOCTYPE html>
<html>
<head>
  <style>
    #container {
      width: 200px;
      height: 200px;
      overflow: scroll;
    }
    #content {
      width: 750px;
      height: 10000px;
      background-color: blue;
    }
  </style>
  <div id="container">
    <div id="content"></div>
  </div>
  <script type="text/javascript">
    if (window.internals)
      internals.settings.setScrollAnimatorEnabled(true);

    requestAnimationFrame(() => {
      if (container.scrollTo)
        container.scrollTo({left: 750, top: 10000, behavior: 'smooth'});
      else
        console.log('ERROR: no container.scrollTo');
    });
  </script>
</head>
</html>