Remove the GetCaption dataprovider method

xfa/fwl/core/cfwl_combobox.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 XFA_FWL_CORE_CFWL_COMBOBOX_H_
 #define XFA_FWL_CORE_CFWL_COMBOBOX_H_
 
 #include <memory>
 #include <vector>
 
 #include "xfa/fwl/core/cfwl_widget.h"
 #include "xfa/fwl/core/ifwl_combobox.h"
 
 class CFWL_ComboBox : public CFWL_Widget, public IFWL_ComboBox::DataProvider {
  public:
   explicit CFWL_ComboBox(const IFWL_App* pApp);
   ~CFWL_ComboBox() override;
 
   void Initialize();
 
-  // IFWL_Widget::DataProvider
-  void GetCaption(IFWL_Widget* pWidget, CFX_WideString& wsCaption) override;
-
   // IFWL_ListBox::DataProvider
   int32_t CountItems(const IFWL_Widget* pWidget) const override;
   CFWL_ListItem* GetItem(const IFWL_Widget* pWidget,
                          int32_t nIndex) const override;
   int32_t GetItemIndex(IFWL_Widget* pWidget, CFWL_ListItem* pItem) override;
   uint32_t GetItemStyles(IFWL_Widget* pWidget, CFWL_ListItem* pItem) override;
   void GetItemText(IFWL_Widget* pWidget,
                    CFWL_ListItem* pItem,
                    CFX_WideString& wsText) override;
   void GetItemRect(IFWL_Widget* pWidget,
@@ skipping 55 matching lines @@
 
   void GetBBox(CFX_RectF& rect);
   void EditModifyStylesEx(uint32_t dwStylesExAdded, uint32_t dwStylesExRemoved);
 
  private:
   std::vector<std::unique_ptr<CFWL_ListItem>> m_ItemArray;
   FX_FLOAT m_fMaxListHeight;
 };
 
 #endif  // XFA_FWL_CORE_CFWL_COMBOBOX_H_