LayoutTests/fast/shadow-dom/media-query-in-shadow-style.html

<iframe src=resources/media-query-in-shadow-style-frame.html width=150 height=50></iframe><br>
<iframe src=resources/media-query-in-shadow-style-frame.html width=300 height=50></iframe><br>
<iframe src=resources/media-query-in-shadow-style-frame.html width=300 height=50 onload='resize(event.target, 150)'></iframe><br>
<iframe src=resources/media-query-in-shadow-style-frame.html width=150 height=50 onload='resize(event.target, 300)'></iframe><br>
<script>
if (window.testRunner)
    testRunner.waitUntilDone();

let resizeCount = 2;

function resize(frame, size)
{
    setTimeout(() => {
        frame.width = size;
        if (!--resizeCount)
            testRunner.notifyDone();
    }, 10);
}
</script>