<!DOCTYPE html>
<script src="resources/srcset-helper.js"></script>
<style>
.foo {
width: 100px;
height: 100px;
content: url('resources/red-100-px-square.png');
}
</style>
<div>
This test passes if the div below is a 100px red square.
</div>
<br>
<div class="foo"></div>