<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>Page Visibility API is Read Only</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script type="text/javascript" src="resources/pagevistestharness.js"></script>
<script type="text/javascript">
setup({ explicit_done: true });
function onload_test()
{
//check for feature definition first before attempting to overwrite
pv_test();
//Check document.hidden
document.hidden = "new value";
test_true(document.hidden !== "new value", 'document.hidden is read only.');
//Check document.visibilityState
document.visibilityState = "new value";
test_true(document.visibilityState !== "new value",
"document.visibilityState is read only.");
done();
}
</script>
</head>
<body onload="onload_test();">
<h1>Description</h1>
<p>This test validates that the Page Visibility attributes are read only.</p>
<div id="log"></div>
</body>
</html>