backout Bug 533840, since it added a randomly failing test
backout Bug 533840, since it added a randomly failing test

--HG--
extra : rebase_source : c9f9de9148b5a52bf7013b543035626d959c6e5a
bug 789919, (snow-white) make addref/release of CCable objects faster by removing indirect refcnt increase/decrease, r=mccr8, test changes r=ehsan

--HG--
extra : rebase_source : 2a3b22425c14d6daedc91d62a652c34431acd2fb