UserAgent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/53.0.2785.113 Safari/537.36

Steps to reproduce the problem:
1. create 2 divs with shadow roots
2. append an input into the inner div light dom
3. insert inner div into outer div light dom
4. append outer div in body, add other focusables
5. TAB through the focusables

var template = document.createElement('template');
template.content.appendChild(document.createElement('slot'));

var inner = document.createElement('div');
inner.attachShadow({mode: 'open'}).appendChild(document.importNode(template.content, true));
inner.appendChild(document.createElement('input'));

var outer = document.createElement('div');
outer.attachShadow({mode: 'open'}).appendChild(document.importNode(template.content, true));
outer.appendChild(inner);

document.body.appendChild(document.createElement('input'));
document.body.appendChild(outer);
document.body.appendChild(document.createElement('input'));

What is the expected behavior?
focus should move outside the shadow root

What went wrong?
focus is trapped into `inner` div

Did this work before? N/A 

Chrome version: 53.0.2785.113  Channel: n/a
OS Version: OS X 10.11.6
Flash Version: Shockwave Flash 23.0 r0