chromium/third_party/blink/web_tests/svg/custom/font-face-move.svg

<svg xmlns="http://www.w3.org/2000/svg">
    <defs id="defs">
        <font id="a">
            <font-face id="bfont" font-family="b" />
        </font>
    </defs>
    <text font-family="b">PASS</text>
    <script>
    if (window.testRunner)
        testRunner.dumpAsText();
    var defs = document.getElementById("defs");
    var bfont = document.getElementById("bfont");
    defs.appendChild(bfont);
    </script>
</svg>