Fieldset and ShadowRoot
crbug.com/512941
by int32_t
HTML
<div>Case 1:</div>
<div id=host1></div>
<div>Case 2:</div>
<fieldset disabled>
<div id=host2></div>
</fieldset>
JavaScript
var host = document.querySelector('#host1');
var root = host.createShadowRoot();
root.innerHTML = '<fieldset disabled><input type=checkbox></fieldset>';
var host = document.querySelector('#host2');
root = host.createShadowRoot();
root.innerHTML = '<input type=checkbox>';