chromium/third_party/blink/web_tests/fast/multicol/float-with-margin-moved-by-child-block-and-unbreakable.html

<!DOCTYPE html>
<script src="../../resources/check-layout.js"></script>
<p>Test that space is reserved for the top margin of a float that is pushed to the next column. In
    this test, there are two reasons why the float needs to be pushed to next column: It's
    unbreakable, and its first block doesn't fit in the previous column.</p>
<p>There should be a blue rectangle below.</p>
<div id="test" style="position:relative; -webkit-columns:3; -webkit-column-gap:0; column-fill:auto; width:150px; height:90px; line-height:20px;">
    <div style="margin-top:5px; margin-bottom:15px; height:40px; background:blue;"></div>
    <br>
    <div data-offset-y="5" style="float:left; width:100%; margin-top:5px; -webkit-column-break-inside:avoid; background:blue;">
        <div data-offset-y="5">
            <br><br>
        </div>
    </div>
</div>
<script>
    checkLayout("#test");
</script>