Backed out changeset b92529577644 (bug 895395) on suspicion of causing shutdown hangs on OS X
Backed out changeset 998d2d5e743d (bug 919878) on suspicion of causing shutdown hangs on OS X
Backed out changeset 77f53f9d3099 (bug 935784) on suspicion of causing shutdown hangs on OS X
Merge mozilla-central and fx-team
Bug 940262 - Hide .tab-background in the early tabopen animation phase and show it after a short offset