chromium/third_party/blink/web_tests/css3/filters/backdrop-filter-plus-mask.html

<!DOCTYPE html>
<meta charset="utf-8">
<title>backdrop-filter: Correctly apply masks/clips to backdrop-filter content</title>
<link rel="author" href="mailto:[email protected]">
<link rel="help" href="https://drafts.fxtf.org/filter-effects-2/#BackdropFilterProperty">
<link rel="match"  href="backdrop-filter-plus-mask-ref.html">

<!--Expected: A black circle.-->

<!-- TODO(978481): Convert this back to WPT test. See crbug.com/978481 for
  an implementation in WPT that is waiting for the WPT Fuzzy Matching feature.
-->

<div></div>

<svg>
  <clipPath id="heart" clipPathUnits="objectBoundingBox">
    <path d="M0.5,1
      C 0.5,1,0,0.7,0,0.3
      A 0.25,0.25,1,1,1,0.5,0.3
      A 0.25,0.25,1,1,1,1,0.3
      C 1,0.7,0.5,1,0.5,1 Z" />
  </clipPath>
</svg>

<style>
div {
  position: absolute;
  top: 100px;
  left: 50px;
  width: 200px;
  height: 200px;
  backdrop-filter: invert(1);
  clip-path: url(#heart);
}
</style>