page_with_contenteditable_in_cross_site_subframe.html

<html>
<head></head>
<body>
This page has a cross-site subframe that contains a contenteditable div.
<iframe id='subframe' src='/cross-site/b.com/page_with_contenteditable.html'></iframe>
</body>
</html>

chromium/chrome/test/data/page_with_contenteditable_in_cross_site_subframe.html