clipping for wxMac cleaned up

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@29392 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/generic/laywin.h

@@ -184,6 +184,10 @@ public:
     // Called by layout algorithm to retrieve information about the window.
     void OnQueryLayoutInfo(wxQueryLayoutInfoEvent& event);
 
+#ifdef __WXMAC__
+    virtual bool MacClipChildren() const { return true ; }
+#endif
+
 private:
     void Init();