Bug 913527, part 3 - Check for collection in progress in Collect. r=smaug
listener refactor part 0 - Move root logging into ScanRoots
listener refactor part 1: Log garbage at the same time we log roots
listener refactor part 2 - Sink shutdown listener selection into Collect
listener refactor part 3 - Sink listener selection into BeginCollection
more cleanup, part 1 - Remove unused method
more cleanup, part 2 - Make a bunch of cycle collector methods private
Store the listener pointer on the nsCC data structure
Allocate the graph builder on the heap
Add an AutoBool class to guard scaninprogress, hoist out MarkRoots and ScanRoots