Backed out 6 changesets (bug 939318) for Windows xpcshell failures on a CLOSED TREE.

Backed out changeset faece15110ef (bug 939318)
Backed out changeset ecc0368d9283 (bug 939318)
Backed out changeset 4dcb889cf913 (bug 939318)
Backed out changeset 2fe8c65c26c2 (bug 939318)
Backed out changeset 0b9c1bbc7826 (bug 939318)
Backed out changeset fc191ae0a0e8 (bug 939318)