chromium/third_party/blink/web_tests/http/tests/svg/resources/svg-use-defs-rect.svg

<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
    <defs id="d">
        <linearGradient id="maskedGradient"></linearGradient>
        <rect id="masked" fill="url(#maskedGradient)"/>
        <mask id="mask"></mask>
    </defs>
    <use xlink:href="#masked" mask="url(#mask)"/>
</svg>