Backed out 7 changesets (bug 966591) for mochitest leaks on a CLOSED TREE.

Backed out changeset b44289e756fc (bug 966591)
Backed out changeset c428b424ef95 (bug 966591)
Backed out changeset 9ac56da10646 (bug 966591)
Backed out changeset 81ba9bddd84e (bug 966591)
Backed out changeset 0c66968c2edd (bug 966591)
Backed out changeset 261a1ca9045c (bug 966591)
Backed out changeset 895728963f16 (bug 966591)