UserAgent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/50.0.2661.102 Safari/537.36

Steps to reproduce the problem:
1. Visit this page:
https://rickyromero.com/tmp/flickering-menu.html

2. Open the menu.

To repeat, click off the menu to remove focus, then open the menu again.

What is the expected behavior?
Menus should be rendered without flashing repeatedly and locking up the browser.

What went wrong?
Menu contents flash repeatedly during the CSS transition and the browser locks up.

A recording of the issue is available here:
https://rickyromero.com/tmp/flickering-menu.mp4

Did this work before? Yes Chrome 49

Chrome version: 50.0.2661.102  Channel: stable
OS Version: OS X 10.11.5
Flash Version: Shockwave Flash 21.0 r0

The menu rendering behaves correctly in stable Firefox (46.0.1) and Safari (9.1.1). Unsure if the issue appears on Chrome for Windows. I've chosen a longer CSS transition to guarantee that the issue will appear.

This issue also appears on the "Size" menu on this Amazon page, though less reliably:
http://www.amazon.com/ASICS-Venture-Running-Carbon-Orange/dp/B00YDI7XCS/ref=sr_1_1?s=apparel&ie=UTF8&qid=1464198505&sr=1-1&nodeID=7141123011&keywords=asics+shoes