Bug 899022, cycle collect WindowRoot's window, r=mccr8

--HG--
extra : rebase_source : d223a51a2f928694dc6c3c79bd73b971329004db
Bug 894973 - mach command to dump environment and build config info; r=ted

DONTBUILD (NPOTB)

--HG--
extra : rebase_source : 27e23637b6e015b28f72078ab074624ea134318b
Bug 786307: Implement RTCP MUX in MediaPipeline r=ekr
Bug 902532: Use NS_CopyNativeToUnicode to convert dictionary filename to UTF-16 on Windows. r=ehsan