<html>
<head>    
<script>
    window.onload = () => {
      if (window.testRunner) {
        testRunner.waitUntilDone();
        testRunner.setBackingScaleFactor(2, () => setTimeout(() => testRunner.notifyDone(), 0));
      }
    }
</script>

<style>
    #foo {
        width:100px;
        height:100px;
        background-image: radial-gradient(red, blue);
    }
</style>
</head>

<body>
    <div>This test passes if the div below is a 100px green-white gradient square when devicePixelRatio is 1, a radial red-blue square when devicePixelRatio is 2, and a blue square when devicePixelRatio is 3.</div>
    <div id=foo></div>
</body>
</html>