chromium/third_party/blink/web_tests/accessibility/accessibility-object-detached.html

<!DOCTYPE HTML>
<html>
<body>
<script src="../resources/js-test.js"></script>

<canvas id="canvas"></canvas>

<div id="console"></div>
<script>
description("This test makes sure that AccessibilityObjects are detached when the node they point to is detached.");

if (window.testRunner && window.accessibilityController) {
    testRunner.dumpAsText();

    // Create a button on the page, focus it and get its accessibility role.
    var button = document.createElement('button');
    document.body.appendChild(button);
    button.focus();
    window.axElement = accessibilityController.focusedElement;
    window.expectedButtonRole = axElement.role;

    // Now remove the node from the tree and get the role of the detached accessibility object.
    // We detect that it's detached just by checking that the role is different (empty or unknown).
    document.body.removeChild(button);
    window.expectedDetachedRole = axElement.role;
    shouldBeTrue("expectedButtonRole != expectedDetachedRole");
}

</script>

</body>
</html>