<html>
<head>
    <head>
    <script>
        function startTest() {
            if (window.testRunner) {
                testRunner.waitUntilDone();
                testRunner.setBackingScaleFactor(2, finishTest);
            }
        }

        function finishTest() {
            var test = document.getElementById("foo");
            test.innerHTML = window.devicePixelRatio;
            setTimeout(function() { testRunner.notifyDone(); }, 0);
        }
    </script>
    
<style>
    #foo {
        width:100px;
        height:100px;
        background-image: -webkit-image-set(url('resources/blue-100-px-square.png') 1x, url('resources/green-200-px-square.png') 2x);
    }
</style>
</head>

<body onload="startTest();">
    <div>This test passes if the div below is a blue 100px square when the deviceScaleFactor is 1, and if it is a 100px green square when the deviceScaleFactor is 2. When run in the test harness, this test is distinct from image-set-as-background, because it ensures that the green image loads dynamically when the scale factor changes.</div>
    <div id=foo></div>
</body>
</html>