page_with_allowfullscreen_frame.html

<!DOCTYPE html>
<html>
<body>
  This page has one cross-site iframe with permission to enter fullscreen.
  <iframe id="child-0" src="/cross-site/b.com/title1.html" allowFullscreen></iframe>
</body>
</html>

chromium/content/test/data/page_with_allowfullscreen_frame.html