Mac: Fix compile error in cefclient_osr_widget_mac.mm when using the 10.6 SDK.
Mac: Fix compile error in cefclient_osr_widget_mac.mm when using the 10.6 SDK.

git-svn-id: 66addb63d0c46e75f185859367c4faf62af16cdd@1335 5089003a-bbd8-11dd-ad1f-f1f9622dbc98

kuscsik/chromiumembedded,denzp/cef3,denzp/cef3,denzp/cef3,denzp/cef3,kuscsik/chromiumembedded,kuscsik/chromiumembedded,kuscsik/chromiumembedded