Use virtual function to retrieve interface pointer

xfa/fwl/lightwidget/cfwl_edit.h

Index: xfa/fwl/lightwidget/cfwl_edit.h
diff --git a/xfa/fwl/lightwidget/cfwl_edit.h b/xfa/fwl/lightwidget/cfwl_edit.h
index a6db961a2b7fadccc71261f97faccb45043785dc..a9a466a49acd17d3166e50656b2b7447e580c97d 100644
--- a/xfa/fwl/lightwidget/cfwl_edit.h
+++ b/xfa/fwl/lightwidget/cfwl_edit.h
@@ -9,6 +9,7 @@
 
 #include <vector>
 
+#include "xfa/fwl/basewidget/ifwl_edit.h"
 #include "xfa/fwl/lightwidget/cfwl_widget.h"
 
 class CFWL_WidgetProperties;
@@ -19,6 +20,9 @@ class CFWL_Edit : public CFWL_Widget {
   CFWL_Edit();
   ~CFWL_Edit() override;
 
+  IFWL_Edit* GetWidget() override;
+  const IFWL_Edit* GetWidget() const override;
+
   static CFWL_Edit* Create();
   FWL_Error Initialize(const CFWL_WidgetProperties* pProperties = nullptr);
   FWL_Error SetText(const CFX_WideString& wsText);