LayoutTests/svg/clip-path/clip-path-clip.svg

<svg xmlns="http://www.w3.org/2000/svg">
<clipPath id="clip2">
  <rect x="50" y="50" width="100" height="100"/>
</clipPath>
<clipPath id="clip1" clip-path="url(#clip2)">
  <circle cx="100" cy="100" r="100"/>
</clipPath>
<rect width="200" height="200" fill="green" clip-path="url(#clip1)"/>
</svg>