<html>
<title>sandboxed_frames</title>
<head></head>
  <body>
    <iframe id="child-1" sandbox></iframe>
    <iframe id="child-2" sandbox="allow-scripts"></iframe>
    <iframe id="child-3" sandbox="allow-scripts allow-same-origin" src="frame_tree/1-3.html"></iframe>
  </body>
</html>