Bug 863319 - Improve assertions in browser_image mochitest. r=joe

--HG--
extra : rebase_source : bf323152a21613bf20d1ff2456520346bf1460b1
Bug 862431 - Please upload new emulator to tooltool. r=jgriffin
Merge birch to m-c.
Bug 865255 - Fix regression in sdcard availability detections. r=dougt
Bug 858582 - Prevent callsite cloning of callsite clones. (r=bhackett)
Bug 861904. (r=sstangl)
Merge the last PGO-green inbound changeset to m-c.
Merge m-c to inbound.
Bug 865004 - Disconnect the AudioNode from the graph before deleting it; r=bzbarsky