chromium/third_party/blink/web_tests/fast/css/resources/font-face-local-file-frame.html

<script>
var font = new FontFace('test', 'url(../../../resources/Ahem.ttf)');
font.load().then(function() {
    window.parent.postMessage('PASS: ahem loaded successfully', '*');
}).catch(function() {
    window.parent.postMessage('FAIL: ahem load failed', '*');
});
</script>