update-widget-positions-on-nested-frames-and-scrollers.html

<!DOCTYPE html>
<html>
<head>
  <style>
    iframe {
      top: 0;
      left: 0;
      height: 500px;
      width: 500px;
      border: 2px solid black;
    }
  </style>
  <script>
    if (window.testRunner)
      testRunner.waitUntilDone();
    if (window.internals)
      internals.settings.setPreferCompositingToLCDTextEnabled(true);
  </script>
</head>

<!--
  This test scrolls a nested iframe down, then clicks on a select element. If
  updateWidgetPositions() hasn't been called properly, this will cause the frame
  to scroll to where it thinks the element being clicked on is. Javascript
  execution will start in the onload handler in
  resources/update-widget-positions-on-nested-frames-and-scrollers-inner-frame.html.
-->
<body>
  <iframe src="resources/update-widget-positions-on-nested-frames-and-scrollers-outer-frame.html"></iframe>
</body>
</html>

chromium/third_party/blink/web_tests/compositing/overflow/update-widget-positions-on-nested-frames-and-scrollers.html