chromium/third_party/blink/web_tests/scrollbars/custom-scrollbar-enable-changes-thickness-with-iframe.html

<!DOCTYPE html>
<style>
::-webkit-scrollbar { height: 15px; width: 15px; }
::-webkit-scrollbar:disabled { display: none; }
</style>

This test verifies that layout runs correctly when custom scrollbar styles produce
different thickness for the enabled and disabled states, and are inherited by an iframe.
<br><br>
The test passes if it does not crash.

<iframe width=800 height=600 srcdoc=""></iframe>
<script>
if (window.testRunner) {
    testRunner.dumpAsText();
}
</script>