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chromium/content/test/data/sandboxed_frames_csp.html 

<html>
<title>sandboxed_frames</title>
<head></head>
  <body>
    <iframe id="child-1" src="sandboxed_child_frame.html"></iframe>
    <iframe id="child-2" sandbox="allow-scripts allow-pointer-lock allow-orientation-lock" src="sandboxed_child_frame.html"></iframe>
  </body>
</html>