In bug 1313933, we removed the session store black magic that RDM used to do in
order to hide the container tab.
Unfortunately, that fix appears to have been imperfect. Session store has a
fallback path that can still record the current URL, causing the container URL
to be recorded anyway, even though we asked nicely to please not do that.
In this change, we try a fresh approach of wedging the session history listener
for the container tab so it can't record anything. This avoids the racy
approach that was used before bug 1313933 while still appearing to block the
container URL from being recorded.
MozReview-Commit-ID: JZTYzMAvaEM
d1e2853625