<!DOCTYPE HTML>
<html>
<head>
  <title>Resize Reflow Test</title>
</head>
<body>

<div style="-moz-column-width: 12em;
            border: silver solid;
            width: 30em" id="outer">
x <div style="border: dotted;
              background: aqua;
              color: gray;">
        blah<br>
        blah<br>
        blah<br>
        blah
  </div>
</div>

<script>
document.body.offsetWidth;
n = document.getElementById("outer").firstChild;
n.data = ' ';
</script>

</body>
</html>