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. Open webpage https://funag.github.io/
2. Open devtools
3. Go to timeline tab
4. Do a page refresh, timeline tab shows — recording timeline data
5. Timeline finishes has says 'retrieving timeline...' 

What is the expected behavior?
Retrieving timeline should happen in a finite amount of time

What went wrong?
I think its something to do with service workers as otherwise devtools works fine

Did this work before? Yes 

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