<!DOCTYPE html>
<style>
.multicol {
margin: 3em 0;
width: 60px;
-webkit-column-width: 20px;
-webkit-column-gap: 0;
column-fill: auto;
height: 60px;
}
.square {
width: 20px;
height: 20px;
background: green;
}
.layer { will-change: transform; }
</style>
<p>If no compositing were present, there should be two green squares below. Since some elements are composited, and therefore not fragmented, the output is different.</p>
<div class="multicol">
<div class="square"></div>
<div class="square"></div>
<div class="layer"> <!-- from first to second column -->
<div class="square"></div>
<div class="square"></div>
</div>
<div class="square"></div>
<div class="layer"> <!-- from second to third column -->
<div class="square"></div>
<div class="square"></div>
</div>
<div class="square"></div>
<div class="square"></div>
</div>
<div class="multicol">
<div class="square"></div>
<div class="square"></div>
<div class="layer"> <!-- from first to third column -->
<div class="square"></div>
<div class="square"></div>
<div class="square"></div>
<div class="square"></div>
<div class="square"></div>
</div>
<div class="square"></div>
<div class="square"></div>
</div>