third_party/WebKit/LayoutTests/svg/masking/mask-type-not-set.svg

<svg xmlns="http://www.w3.org/2000/svg">
<defs>
        <mask id="mask">
                <rect width="200" height="200" fill="black"/>
                <!-- rgb #808080 yields a 50% luminance -> 50% output color -->
                <rect width="100" height="100" fill="#808080"/>
                <rect x="100" y="100" width="100" height="100" fill="#808080"/>
        </mask>
</defs>
<rect width="200" height="200" fill="#00FF00" mask="url(#mask)"/>
</svg>