chromium/third_party/blink/web_tests/svg/custom/rect-negative-corner-radii.svg

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<svg xmlns="http://www.w3.org/2000/svg" version="1.0" width="500" height="500">
    <rect  x="50" y="50"  width="400" height="400" rx="-50"  ry="-50"  fill="#00ff00" />
    <rect x="150" y="100" width="200" height="300" rx="-100" ry="50" fill="#0000ff" />
    <rect x="200" y="150" width="100" height="200" rx="50" ry="-100" fill="#ff0000" />
</svg>