<!DOCTYPE html>
<html>
<body>
<script src="../../resources/js-test-pre.js"></script>
<script>
description("This test checks the onvisibilitychange event handler attribute on Document.");

var jsTestIsAsync = true;

function makePageHidden() {
    if (window.testRunner)
        testRunner.setPageVisibility("hidden");
}

function checkIsPageVisible() {
    shouldBeEqualToString("document.visibilityState", "visible");
    shouldBeFalse("document.hidden");
}

function checkIsPageHidden() {
    shouldBeEqualToString("document.visibilityState", "hidden");
    shouldBeTrue("document.hidden");
}

function startTest() {
    document.onvisibilitychange = function() {
        checkIsPageHidden();
        document.onvisibilitychange = null;
        if (window.testRunner)
            testRunner.resetPageVisibility();
        finishJSTest();
    };
    checkIsPageVisible();
    makePageHidden();
}

startTest();
</script>
<script src="../../resources/js-test-post.js"></script>
</body>
</html>