chromium/third_party/blink/web_tests/fast/events/max-tabindex-focus.html

<!DOCTYPE html>
<script src="../../resources/testharness.js"></script>
<script src="../../resources/testharnessreport.js"></script>
<script>
var tabTest = async_test("Tests that an element with the maximum tabIndex value can be focused.");

function success()
{
  tabTest.done();
}

setTimeout(function () {
  tabTest.step(function () {
    var element = document.getElementById('focusMe')
    element.focus();

    document.getElementById("elementWithMaxTabIndex").onfocus = success;
    eventSender.keyDown("\t");
  });
}, 10);
</script>
<body>
<input id="focusMe" tabindex="1">
<input id="elementWithMaxTabIndex" tabindex="2147483647">
</body>