Codebase Browser
chromium
Go to App

chromium/third_party/blink/web_tests/animations/custom-properties/url-type-interpolation.html 

<!DOCTYPE html>
<meta charset="UTF-8">
<style>
.parent {
  --url: url('http://parent.txt');
}
.target {
  --url: url('http://underlying.txt');
}
</style>
<body>
<script src="../interpolation/resources/interpolation-test.js"></script>
<script>
CSS.registerProperty({
  name: '--url',
  syntax: '<url>',
  initialValue: "url('http://initial.txt')",
  inherits: false,
});

assertNoInterpolation({
  property: '--url',
  from: neutralKeyframe,
  to: "url('http://value.txt')",
});

assertNoInterpolation({
  property: '--url',
  from: 'initial',
  to: "url('http://value.txt')",
});

assertNoInterpolation({
  property: '--url',
  from: 'inherit',
  to: "url('http://value.txt')",
});

assertNoInterpolation({
  property: '--url',
  from: 'unset',
  to: "url('http://value.txt')",
});

assertNoInterpolation({
  property: '--url',
  from: "url('http://a.txt')",
  to: "url('http://b.txt')",
});
</script>
</body>