palemoon-dev/platform/layout/reftests/svg/mask-on-outflowElement.svg

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  <rect x="100" y="100" width="100" height="100" style="stroke:none; fill: #ffffff"/>
  <rect x="200" y="200" width="100" height="100" style="stroke:none; fill: #ffffff"/>
  <rect x="300" y="300" width="100" height="100" style="stroke:none; fill: #ffffff"/>
</svg>