chromium/third_party/blink/web_tests/fast/multicol/mixed-positioning-stacking-order.html

<!doctype html>
<html>
<body>
<div style="width:210px; height:200px; border:5px solid black; -moz-column-width:100px; -moz-column-gap:10px; -webkit-column-width:100px; -webkit-column-gap:10px; column-width:100px; column-gap:10px; column-fill:auto;">

<div style="position:relative;">
<div style="position:absolute;top:0;left:0; height:400px; width:100px">
<div style="width:100px;height:100px;background-color:purple;">3</div>
<div style="height:200px"></div>
<div style="width:100px;height:100px;background-color:purple;">3</div>
</div>
<div style="position:absolute; z-index:1; background-color:lightblue; width:100%; height:200px; top:100px">1</div>

<div style="position:fixed;background-color:gold;left:68px;top:13px;height:200px;width:100px">2</div>
</div>
</div>