Bug 751575 - Disable test_pb_notification_ipc.js for permafailing in a CPG world; r=jst CLOSED TREE

docshell/test/unit_ipc/xpcshell.ini

@@ -3,3 +3,5 @@ head =
 tail =
 
 [test_pb_notification_ipc.js]
+# Bug 751575: Perma-fails with: command timed out: 1200 seconds without output
+skip-if = true