Fixes for split tree when using generic tree control

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_2_8_BRANCH@51154 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

contrib/include/wx/gizmos/splittree.h

@@ -80,6 +80,13 @@ public:
     // In case we're using the generic tree control.
     virtual int GetScrollPos(int orient) const;
 
+    // Override to suppress vertical scrollbar
+    virtual void SetScrollbar(int orient,
+                               int pos,
+                               int thumbVisible,
+                               int range,
+                               bool update);
+
 //// Helpers
     void HideVScrollbar();