Added IsOwnGtkWindow() to wxChoice for mouse click interception.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_2_4_BRANCH@21744 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/gtk1/choice.h

@@ -68,6 +68,7 @@ protected:
 
     virtual wxSize DoGetBestSize() const;
 
+    virtual bool IsOwnGtkWindow( GdkWindow *window );
 private:
     // common part of Create() and DoAppend()
     size_t GtkAppendHelper(GtkWidget *menu, const wxString& item);