downloadable-font-scoped-to-document.html

 <!DOCTYPE html>

<html class="reftest-wait">
    <head>
        <title>CSS fonts: Web fonts loaded in a document are not available in other documents</title>
        <link rel="author" title="Martin Robinson" href="[email protected]">
        <link rel="author" title="Mukilan Thiyagarajan" href="[email protected]">
        <link rel="match" href="downloadable-font-scoped-to-document-ref.html">
        <link rel="help" href="https://drafts.csswg.org/css-fonts/#font-face-rule">
    </head>

    <body>
        <p>Test passes if Ahem is only used in the first iframe.</p>
        <iframe id="iframe1" src="support/iframe-using-ahem-as-web-font.html"></iframe>
        <iframe id="iframe2" src=""></iframe>

        <script>
            // Delay the loading of the second iframe to make it more likely that the font
            // has loaded properly into the first iframe.
            iframe1.onload = () => {
                iframe2.src ="support/iframe-missing-font-face-rule.html";
                document.documentElement.classList.remove('reftest-wait');
            };
        </script>
    </body>

</html>

chromium/third_party/blink/web_tests/external/wpt/css/css-fonts/downloadable-font-scoped-to-document.html