Remove unused list data pointer

xfa/fwl/cfwl_listbox.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/fwl/cfwl_listbox.h"
 
 #include <algorithm>
 #include <memory>
@@ skipping 1022 matching lines @@
   return pItem ? static_cast<CFWL_ListItem*>(pItem)->m_dwStates : 0;
 }
 
 void CFWL_ListBox::GetItemRect(CFWL_Widget* pWidget,
                                CFWL_ListItem* pItem,
                                CFX_RectF& rtItem) {
   if (pItem)
     rtItem = static_cast<CFWL_ListItem*>(pItem)->m_rtItem;
 }
 
-void* CFWL_ListBox::GetItemData(CFWL_Widget* pWidget, CFWL_ListItem* pItem) {
-  return pItem ? static_cast<CFWL_ListItem*>(pItem)->m_pData : nullptr;
-}
-
 void CFWL_ListBox::SetItemStyles(CFWL_Widget* pWidget,
                                  CFWL_ListItem* pItem,
                                  uint32_t dwStyle) {
   if (pItem)
     static_cast<CFWL_ListItem*>(pItem)->m_dwStates = dwStyle;
 }
 
 void CFWL_ListBox::SetItemRect(CFWL_Widget* pWidget,
                                CFWL_ListItem* pItem,
                                const CFX_RectF& rtItem) {
@@ skipping 64 matching lines @@
 
 void CFWL_ListBox::DeleteAll() {
   m_ItemArray.clear();
 }
 
 uint32_t CFWL_ListBox::GetItemStates(CFWL_ListItem* pItem) {
   if (!pItem)
     return 0;
   return pItem->m_dwStates | pItem->m_dwCheckState;
 }