spohl (cc-ed) let me know that he's going to be reverting https://bugzilla.mozilla.org/show_bug.cgi?id=967970 and landing https://bugzilla.mozilla.org/show_bug.cgi?id=1405577 to address issues like https://bugzilla.mozilla.org/show_bug.cgi?id=1418903
In particular, reverting the first issue prevent window title disk leaks, but the new patch should still address that need.
-tom