UserAgent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/49.0.2623.110 Safari/537.36

Steps to reproduce the problem:
1. Open Chrome. Click the green icon in the top left to enter what I call "OS X fullscreen".
2. Now visit http://s.codepen.io/enjikaka/debug/LNQWLW
3. Click button to enter "state two", click button to enter fullscreen. Press ESC to get out of fullscreen and to state two. Observe how you are taken to state one instead of state two.

What is the expected behavior?
1. Make sure you are not in "OS X fullscreen", i.e. normal windowed steps.
2. Repet step 2 and 3 from "Steps to reproduce the problem"
3. You are taken back to state two, as you should.

What went wrong?
OS X fullscreen and the implementation of the Fullscreen API in Chrome are not playing nicely together.

Did this work before? N/A 

Chrome version: 49.0.2623.110  Channel: stable
OS Version: OS X 10.11.4
Flash Version: Shockwave Flash 21.0 r0

This might have to do with ESC not being handled correctly by Chrome in "HTML5 fullscreen" as compared to Chrome on Windows. onFullscreenChange steals to ESC handling from keyUp event on document. You can try this by commenting out the onFullscreenChange code in http://codepen.io/enjikaka/pen/LNQWLW and do the steps again.