Fix CFWL_WidgetImpDelegate hierarchy.

xfa/src/fwl/src/basewidget/include/fwl_listboximp.h

Index: xfa/src/fwl/src/basewidget/include/fwl_listboximp.h
diff --git a/xfa/src/fwl/src/basewidget/include/fwl_listboximp.h b/xfa/src/fwl/src/basewidget/include/fwl_listboximp.h
index a2d6e653479848ccae8f588966c0ed4b73bd968e..4695a2caec28a5299bfe5536274946db7a961134 100644
--- a/xfa/src/fwl/src/basewidget/include/fwl_listboximp.h
+++ b/xfa/src/fwl/src/basewidget/include/fwl_listboximp.h
@@ -98,10 +98,10 @@ class CFWL_ListBoxImp : public CFWL_WidgetImp {
 class CFWL_ListBoxImpDelegate : public CFWL_WidgetImpDelegate {
  public:
   CFWL_ListBoxImpDelegate(CFWL_ListBoxImp* pOwner);
-  virtual int32_t OnProcessMessage(CFWL_Message* pMessage);
-  virtual FWL_ERR OnProcessEvent(CFWL_Event* pEvent);
-  virtual FWL_ERR OnDrawWidget(CFX_Graphics* pGraphics,
-                               const CFX_Matrix* pMatrix = NULL);
+  int32_t OnProcessMessage(CFWL_Message* pMessage) override;
+  FWL_ERR OnProcessEvent(CFWL_Event* pEvent) override;
+  FWL_ERR OnDrawWidget(CFX_Graphics* pGraphics,
+                       const CFX_Matrix* pMatrix = NULL) override;
 
  protected:
   void OnFocusChanged(CFWL_Message* pMsg, FX_BOOL bSet = TRUE);