Note that the default values of the prefs are chosen so as to preserve
existing behaviour.
The patch also updates a user-visible warning message, which was
already out of date as of bug 1274991.
MozReview-Commit-ID: AqBBoIucShT
--HG--
extra : rebase_source : 010aa55255d49e4875cb6870f309649a9ca762d5