Backed out changeset 70a72a19cb4b (bug 1093654)
Backed out changeset 1c969fba2f64 (bug 1092979)
Backed out changeset a6540a77d6f7 (bug 1065827)
Backed out changeset c0087ef95dc0 (bug 1065827)
Backed out changeset 4467ecf7bc6b (bug 1065827)
Backed out changeset 9316add97cf2 (bug 1065827)
Backed out changeset 44f27b3c35d4 (bug 1065827)
Backed out changeset aebe859551b3 (bug 1065827) for perma failures in m2 tests on a CLOSED TREE
Bug 1092096 - Separate MSE prefs for MP4 and WebM on a CLOSED TREE.  r=cajbir