chromium/third_party/blink/web_tests/fast/multicol/dynamic/insert-spanner-into-content.html

<!DOCTYPE html>
<script>
    onload = function() {
        var elm = document.getElementById('elm');
        document.body.offsetTop; // trigger layout
        elm.style.display = 'block';
    }
</script>
<p>Test insertion of a spanner into column content, so that the existing column row needs to be split into two.</p>
<p>There should be three lines below with the word "PASS". Letter spacing is expected to vary.</p>
<div style="-webkit-columns:5; -webkit-column-gap:0; width:5em; orphans:1; widows:1;">
    P<br>A<br>S<br>S
    <div id="elm" style="display:none; -webkit-column-span:all;">PASS</div>
    P<br>A<br>S<br>S
</div>