dom-snapshot-scroll-offset-iframe.html

<html>
  <style>
    * {
      margin: 0;
      padding: 0;
      font: 10px Ahem;
    }
  </style>
  <script src="../../resources/ahem.js"></script>
  <body>
    <div style="height:500px;">iframe content</div>
    <div id="fragment">iframe fragment</div>
  </body>
</html>

chromium/third_party/blink/web_tests/inspector-protocol/resources/dom-snapshot-scroll-offset-iframe.html