From:  Boris Zbarsky <bzbarsky@mit.edu>
Date:  26 Feb 2016 22:30:10 Hong Kong Time
Newsgroup:  news.mozilla.org/mozilla.dev.tech.network
Subject:  

Re: request referrer when downgrading from https to http

NNTP-Posting-Host:  173.48.28.145

On 2/26/16 5:43 AM, edanpr@gmail.com wrote:
> I tried using "channel.getProperty("docshell.internalReferrer")" on "http-on-modify-request", but the property never exists.

That property should exist for document loads.  At least modulo whatever 
e10s does here...

-Boris