chromium/third_party/blink/web_tests/fast/css/font-face-used-after-retired.html

<style>
    @font-face {
        font-family: custom;
        src: url(no-such-file.ttf);
    }
</style>
<!-- content: counter(page) causes the style diff to be "detach" -->
<div style="font-family: custom; content: counter(page);">
    <br>PASS
</div>
<script>
    if (window.testRunner) {
        testRunner.dumpAsText();
        testRunner.waitUntilDone();
        // Must wait for the font to fail to load.
        setTimeout(function() { testRunner.notifyDone() }, 100);
    }

    document.execCommand("SelectAll");
</script>