chromium/third_party/blink/web_tests/external/wpt/css/css-variables/variable-created-document.html

<!DOCTYPE html>
<html>
<head>
    <title>Variable added to created document</title>

    <meta rel="author" title="Kevin Babbitt">
    <meta rel="author" title="Greg Whitworth">
    <link rel="author" title="Microsoft Corporation" href="http://microsoft.com" />
    <!-- This is not directly stated in the spec, but still worth testing to ensure it works -->
    <link rel="help" href="http://www.w3.org/TR/css-variables-1/#defining-variables">

    <script src="/resources/testharness.js"></script>
    <script src="/resources/testharnessreport.js"></script>
</head>
<body>
    <div id="target">This text should be green.</div>
    <script type="text/javascript">
        "use strict";

        var workDocument = document.implementation.createHTMLDocument("");
        workDocument.documentElement.innerHTML = "<style id='style'>#target { --c: rgb(0, 136, 0); color: var(--c) }</style>";
        document.head.appendChild(workDocument.getElementById("style"));

        test( function () {
            assert_equals(window.getComputedStyle(document.getElementById("target")).getPropertyValue("--c").trim(), "rgb(0, 136, 0)");
        }, "Variable definition appearing in a created document should work once spliced into the creating document");

        test( function () {
            assert_equals(window.getComputedStyle(document.getElementById("target")).getPropertyValue("color").trim(), "rgb(0, 136, 0)");
        }, "Variable reference appearing in a created document should work once spliced into the creating document");

    </script>
</body>
</html>