Bug 955911. r=roc, a=abillings
Bug 960146. r=kats, r=wesj, a=lsblakk
Bug 963974 - Null mCurrentCompositeTask after calling Cancel() on it. r=mattwoodrow, a=lsblakk
Bug 879239 - More slack at layout/base/tests/test_bug588174.html. r=bz, a=test-only