chromium/third_party/blink/web_tests/fast/multicol/nested-with-forced-breaks-in-eariler-rows.html

<!DOCTYPE html>
<script src="../../resources/check-layout.js"></script>
<p>Test that forced breaks in earlier rows don't confuse the column balancer.</p>
<p>There should be a blue square below.</p>
<div id="outer" style="position:relative; -webkit-column-count:2; -webkit-column-gap:0; width:64px; line-height:32px; height:140px; column-fill:auto;">
    <div style="-webkit-column-count:4; -webkit-column-gap:0;">
        <br>
        <div style="-webkit-column-break-before:always;">
            <br>
            <div style="-webkit-column-break-before:always;"><br></div>
            <div style="-webkit-column-break-before:always;"><br></div>
            <div style="-webkit-column-break-before:always; background:blue;" data-expected-height="128">
                <div data-offset-y="0" data-expected-width="8" data-expected-height="32"><br></div>
                <div data-offset-y="0" data-expected-width="8" data-expected-height="32"><br></div>
                <div data-offset-y="0" data-expected-width="8" data-expected-height="32"><br></div>
                <div data-offset-y="0" data-expected-width="8" data-expected-height="32"><br></div>
            </div>
        </div>
    </div>
</div>
<script>
    checkLayout("#outer");
</script>