See https://bugs.webkit.org/show_bug.cgi?id=39317. As Leopard-specific results are moved from platform/mac to platform/mac-leopard, new Snow Leopard expected results need to be checked in to platform/mac.
Dupin' to 39317, the two tasks are essentially the same (and should be done hand-in-hand). *** This bug has been marked as a duplicate of bug 39317 ***