<html>
<head>
<title>CSS4 media query test: prefers-contrast.</title>
<style type="text/css">
p { color: black; }

@media (prefers-contrast) {
    #a { color: green; }
}
</style>
<script>
if (window.testRunner)
    testRunner.waitUntilDone();

function getUIScript()
{
    return `
    (function() {
        uiController.simulateAccessibilitySettingsChangeNotification(function() {
            uiController.uiScriptComplete("Done");
        });
    })();`
}

function runTest()
{
    if (!window.internals)
        return;

    var element = document.getElementById("a");

    window.internals.settings.forcedPrefersContrastAccessibilityValue = "on";
    document.getElementById("before").textContent = window.getComputedStyle(element).color;
    if (testRunner.runUIScript) {
        testRunner.runUIScript(getUIScript(), function(result) {
            document.getElementById("after").textContent = window.getComputedStyle(element).color;
            testRunner.notifyDone();
        });
    }
}

window.addEventListener("load", runTest, false);
</script>
</head>
<body>
  <p id="a"></p>
  <p>Before was: <span id="before"></span> - should be rgb(0, 0, 0)</p>
  <p>After was: <span id="after"></span> - should be rgb(0, 128, 0)</p>
</body>
</html>