UserAgent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/53.0.2769.0 Safari/537.36

Example URL:
n/a

Steps to reproduce the problem:
1.  set up dummy service-worker (simple console.log as provided by  default polymer project does it for me) 
2. make an XMLHttpRequest from an html to another (allowed) domain(NOTE: The backend server returns the value provided in Origin header as an allowed origin only if it is in the list of allowed domains)
3. Request works up to here
4. Hit refresh
5. Header "Origin" is not sent in request and fails ("XMLHttpRequest cannot load https://api/list. The 'Access-Control-Allow-Origin' header")

If i unregister the service worker, it works again one time till i refresh.

My Service worker is empty for dev (using polymer) so it's code is only a "console.log".

The request is as simple as :

function(rq) {
var xhr = new XMLHttpRequest();
xhr.addEventListener('load', rq.onLoad.bind(this));
xhr.open('GET', rq.url);
xhr.setRequestHeader("Accept","application/json");
xhr.setRequestHeader("Accept-Language","en-US");
xhr.send();
}

What is the expected behavior?
I think that on step (5) the request should have sent the "Origin" header

The exact same page works OK in the current stable version of chrome., but fails on this canary release.

What went wrong?
Header "Origin" was not sent in the request.

Did this work before? Yes Current stable Chrome version works ok.

Chrome version: 53.0.2769.0  Channel: canary
OS Version: OS X 10.11.0
Flash Version: Shockwave Flash 22.0 r0