Backed out 17 changesets (bug 897452) for OSX crashes on a CLOSED TREE.

Backed out changeset 11ad8608bc27 (bug 897452)
Backed out changeset 6bcc629e76f9 (bug 897452)
Backed out changeset b91c858a43f5 (bug 897452)
Backed out changeset 38ba49ee3e97 (bug 897452)
Backed out changeset ea184ef84762 (bug 897452)
Backed out changeset 686cc5122149 (bug 897452)
Backed out changeset 3685a8018e49 (bug 897452)
Backed out changeset be7ef6240068 (bug 897452)
Backed out changeset f95c20e70947 (bug 897452)
Backed out changeset 4a370d2a1c62 (bug 897452)
Backed out changeset 1222f6ab66d2 (bug 897452)
Backed out changeset 5e9d3c681ee9 (bug 897452)
Backed out changeset 3b9ddce12b7a (bug 897452)
Backed out changeset 7aec6387f3e9 (bug 897452)
Backed out changeset eb1fe464fdaf (bug 897452)
Backed out changeset 07deaa53b6fd (bug 897452)
Backed out changeset ddab7d071d69 (bug 897452)