LayoutTests/fast/css/custom-properties/computed-style-access.html - WebKit - Git at Google

 <html>
 <head>
 <style>
 :root { --one: 10px; --another: 20px; }
 </style>
 <body>
 <script>
 document.write(getComputedStyle(document.documentElement).getPropertyValue("--one") + " " + getComputedStyle(document.documentElement).getPropertyValue("--another"))
 </script>
 </body>
 </html.
	<html>
	<head>
	<style>
	:root { --one: 10px; --another: 20px; }
	</style>
	<body>
	<script>
	document.write(getComputedStyle(document.documentElement).getPropertyValue("--one") + " " + getComputedStyle(document.documentElement).getPropertyValue("--another"))
	</script>
	</body>
	</html.