UserAgent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.59 Safari/537.36

Steps to reproduce the problem:
1. Go to https://staging.codecombat.com/
2. Wait for Service Worker to install 
3.  In the Network panel, the requests for all JS files are happening twice

What is the expected behavior?
The JS files need to be loaded once only. Confirmed in Firefox that they are being loaded once only. 

What went wrong?
JS files are being loaded twice for some reason

Did this work before? Yes 

Chrome version: 56.0.2896.0  Channel: canary
OS Version: OS X 10.12.0
Flash Version: 

I am attaching the timeline I recorded too
 

Deleted: TimelineRawData-20161020T184527 0 bytes

TimelineRawData-20161020T184527 0 bytes View Download