The referrer is showing for the new build, You need to change the name of the file from Iron.exe to chrome.exe. I have tried "C:\Program Files (x86)\Google\Chrome\Application\chrome.exe"
--no-referrers and "C:\Program Files (x86)\Google\Chrome\Application\Iron.exe"
--no-referrers.
Proof of referrer leak
http://browserspy.dk/document.php
Only browser that doesn't leak now is Firefox.