<!DOCTYPE HTML>
<meta charset=utf-8>
<title>Layout Instability: observe after user input</title>
<body>
<style>
#myDiv { position: relative; width: 300px; height: 100px; background: blue; }

/* Disable the button's focus ring, which otherwise expands its visual rect by
 * 1px on all sides, triggering a layout shift event.
 */
#button { outline: none; }
</style>
<div id='myDiv'></div>
<button id='button'>Generate a 'click' event</button>
<script src=/resources/testharness.js></script>
<script src=/resources/