Change IFWL_Widget to store a single delegate.

xfa/fxfa/app/xfa_ffbarcode.cpp

Index: xfa/fxfa/app/xfa_ffbarcode.cpp
diff --git a/xfa/fxfa/app/xfa_ffbarcode.cpp b/xfa/fxfa/app/xfa_ffbarcode.cpp
index cd172c5a4da164788c453f2932923f91c38ecc07..8c6dcbfad9514fdc1e81542bf100c650aee3b975 100644
--- a/xfa/fxfa/app/xfa_ffbarcode.cpp
+++ b/xfa/fxfa/app/xfa_ffbarcode.cpp
@@ -7,9 +7,11 @@
 #include "xfa/fxfa/app/xfa_ffbarcode.h"
 
 #include "core/fxcrt/fx_ext.h"
+#include "third_party/base/ptr_util.h"
 #include "xfa/fwl/core/cfwl_barcode.h"
 #include "xfa/fwl/core/fwl_noteimp.h"
 #include "xfa/fwl/core/ifwl_app.h"
+#include "xfa/fxfa/app/cxfa_fffielddelegate.h"
 #include "xfa/fxfa/app/xfa_fffield.h"
 #include "xfa/fxfa/app/xfa_fftextedit.h"
 #include "xfa/fxfa/app/xfa_fwladapter.h"
@@ -132,8 +134,8 @@ FX_BOOL CXFA_FFBarcode::LoadWidget() {
   CFWL_NoteDriver* pNoteDriver = pWidget->GetOwnerApp()->GetNoteDriver();
   pNoteDriver->RegisterEventTarget(pWidget, pWidget);
 
-  m_pOldDelegate = m_pNormalWidget->GetCurrentDelegate();
-  m_pNormalWidget->SetCurrentDelegate(this);
+  m_pNormalWidget->SetDelegate(pdfium::MakeUnique<CXFA_FFFieldDelegate>(
+      m_pNormalWidget->ReleaseDelegate(), this));
   m_pNormalWidget->LockUpdate();
 
   CFX_WideString wsText;