use new style creation (MSWCreateControl() and MSWGetStyle()); adjust the drop down list height after appending/inserting/deleting items

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@25578 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/msw/combobox.h

@@ -100,6 +100,9 @@ public:
 
     WXHWND GetEditHWND() const;
 
+protected:
+    virtual WXDWORD MSWGetStyle(long style, WXDWORD *exstyle) const;
+
 private:
     DECLARE_DYNAMIC_CLASS_NO_COPY(wxComboBox)
 };