chromium/third_party/blink/web_tests/external/wpt/css/filter-effects/backdrop-filter-plus-will-change-opacity.html

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

<p>Expected: A black box.</p>

<div id="filter"></div>

<style>
  #filter {
    width: 100px;
    height: 100px;
    backdrop-filter: invert(1);
    will-change: opacity;
  }
</style>