Zygote : Block SIGCHLD during fork. am: ba4ee699 am: 649225a5 am: b1ef9414 -s ours am: 53ad3493 am: 19689714 am: 22c3317e am: 646a6e0a am: 1656e136 am: 06f9faa9 am: 9aa560c2 am: c29305be am: 7a207851 Change-Id: I571c7648ced9374624e15ccc0822c8a0efde1d45