adding protected inquiry function whether a child window belongs to the 'client' or the 'non-client' area, examples for the latter are toolbar, scrollbars etc

adding another cached clip rect for the real client area


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@33232 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/mac/carbon/frame.h

@@ -111,6 +111,8 @@ protected:
     // the last focused child: we restore focus to it on activation
     wxWindow             *m_winLastFocused;
 
+    virtual bool        MacIsChildOfClientArea( const wxWindow* child ) const ;
+
 private:
     DECLARE_EVENT_TABLE()
     DECLARE_DYNAMIC_CLASS(wxFrame)