chromium/third_party/blink/web_tests/fast/multicol/span/relpos-spanner-with-abspos-child.html

<!DOCTYPE html>
<p>Test that a relatively positioned spanner acts as a containing block for absolutely positioned
    descendants.</p>
<p>Below you should see the word 'PASS' (with large letter spacing). Below the word there should be
    a green square with a black border.</p>
<div style="-webkit-columns:1em; -webkit-column-gap:1em; width:13em; orphans:1; widows:1;">
    P<br>A<br>S<br>S
    <div style="-webkit-column-span:all; position:relative; border:1px solid black; padding:10px; width:100px; height:100px; background:red;">
        <div style="position:absolute; bottom:0; right:0; width:100%; height:100%; background:green;"></div>
    </div>
</div>