Change IFWL_Widget to store a single delegate.

xfa/fxfa/app/xfa_ffbarcode.cpp

 // Copyright 2014 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #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"
 #include "xfa/fxfa/xfa_ffpageview.h"
 #include "xfa/fxfa/xfa_ffwidget.h"
 
 namespace {
 
 const XFA_BARCODETYPEENUMINFO g_XFABarCodeTypeEnumData[] = {
     {0x7fb4a18, L"ean13", XFA_BARCODETYPE_ean13, BC_EAN13},
@@ skipping 102 matching lines @@
 FX_BOOL CXFA_FFBarcode::LoadWidget() {
   CFWL_Barcode* pFWLBarcode = new CFWL_Barcode(GetFWLApp());
   pFWLBarcode->Initialize();
 
   m_pNormalWidget = pFWLBarcode;
   m_pNormalWidget->SetLayoutItem(this);
   IFWL_Widget* pWidget = m_pNormalWidget->GetWidget();
   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;
   m_pDataAcc->GetValue(wsText, XFA_VALUEPICTURE_Display);
   pFWLBarcode->SetText(wsText);
   UpdateWidgetProperty();
   m_pNormalWidget->UnlockUpdate();
   return CXFA_FFField::LoadWidget();
 }
 void CXFA_FFBarcode::RenderWidget(CFX_Graphics* pGS,
@@ skipping 92 matching lines @@
 }
 FX_BOOL CXFA_FFBarcode::OnRButtonDown(uint32_t dwFlags,
                                       FX_FLOAT fx,
                                       FX_FLOAT fy) {
   CFWL_Barcode* pBarCodeWidget = (CFWL_Barcode*)m_pNormalWidget;
   if (!pBarCodeWidget || pBarCodeWidget->IsProtectedType()) {
     return FALSE;
   }
   return CXFA_FFTextEdit::OnRButtonDown(dwFlags, fx, fy);
 }