UserAgent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/56.0.2924.28 Safari/537.36

Steps to reproduce the problem:
1. connect new WebSocket in Service Worker
2. 
3. 

What is the expected behavior?

What went wrong?
55.0.2883.95 - Fail.
56.0.2924.28 beta - Fail.
57 mobile version - Ok.
54 - Ok.
I got this error:
WebSocket connection to 'ws://echo.websocket.org' failed: Unspecified reason

Did this work before? N/A 

Does this work in other browsers? N/A

Chrome version: 56.0.2924.28  Channel: beta
OS Version: 10.0
Flash Version: