Kill dead IFWL_*::Initialize() variants dead.

xfa/include/fwl/basewidget/fwl_listbox.h

 // 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
 
 #ifndef _FWL_LISTBOX_H
 #define _FWL_LISTBOX_H
 class CFWL_WidgetImpProperties;
 class IFWL_Widget;
@@ skipping 92 matching lines @@
                                     FX_DWORD dwCheckState) = 0;
 };
 class IFWL_ListBoxCompare {
  public:
   virtual ~IFWL_ListBoxCompare() {}
   virtual int32_t Compare(FWL_HLISTITEM hLeft, FWL_HLISTITEM hRight) = 0;
 };
 class IFWL_ListBox : public IFWL_Widget {
  public:
   static IFWL_ListBox* Create();
-  FWL_ERR Initialize(IFWL_Widget* pOuter = NULL);
   FWL_ERR Initialize(const CFWL_WidgetImpProperties& properties,
-                     IFWL_Widget* pOuter = NULL);
+                     IFWL_Widget* pOuter);
   int32_t CountSelItems();
   FWL_HLISTITEM GetSelItem(int32_t nIndexSel);
   int32_t GetSelIndex(int32_t nIndex);
   FWL_ERR SetSelItem(FWL_HLISTITEM hItem, FX_BOOL bSelect = TRUE);
   FWL_ERR GetItemText(FWL_HLISTITEM hItem, CFX_WideString& wsText);
   FWL_ERR GetScrollPos(FX_FLOAT& fPos, FX_BOOL bVert = TRUE);
   FWL_ERR* Sort(IFWL_ListBoxCompare* pCom);
 
  protected:
   IFWL_ListBox();
 };
 #endif