<!DOCTYPE html>
<html>
    <head>
        <title>Turn spanner between column rows into regular block</title>
        <script>
            function test() {
                var elm = document.getElementById('elm');
                elm.offsetTop; // trigger layout
                elm.style.webkitColumnSpan = 'none';
                elm.style.columnSpan = 'none';
            }
        </script>
    </head>
    <body onload="test()">
        <p>You should see the word 'PASS' below:</p>
        <div style="float:left;">
            <div style="-webkit-columns:4; columns:4; column-gap:0; -webkit-column-gap:0; orphans:1; widows:1;">
                P
                <div id="elm" style="-webkit-column-span:all; column-span:all;">A</div>
                S<br>S
            </div>
        </div>
    </body>
</html>