<head>
<style>
@import url("data:text/css,#test{display:none;}");
</style>
<script>
if (window.testRunner)
    testRunner.dumpAsText();
function test() {
var s = document.styleSheets;
s[0].cssRules[0].styleSheet.deleteRule(0);
}
</script>
<body onload='test()'>
Test that modifying @import stylesheet through DOM updates style properly. You should see PASS below:
<div id=test>PASS</div>