Backed out 4 changesets (bug 957162, bug 850881, bug 927285, bug 867600) for Mnw failures. a=backout

Backed out changeset c48a12b43fd3 (bug 957162)
Backed out changeset 3feb7f3d481b (bug 850881)
Backed out changeset a88b90e1d8af (bug 927285)
Backed out changeset 99550870b1f5 (bug 867600)