chromium/third_party/blink/web_tests/paint/invalidation/resize-mask-expected.html

<!DOCTYPE html>
<style>
#mask {
  width: 200px;
  height: 100px;
  -webkit-mask-box-image: url(../../fast/backgrounds/resources/dot.png) 3;
  background-color: green;
}
</style>
<div id="mask"></div>