Remove the GetCaption dataprovider method

xfa/fwl/core/ifwl_widget.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_IFWL_WIDGET_H_
 #define XFA_FWL_CORE_IFWL_WIDGET_H_
 
 #include <memory>
@@ skipping 46 matching lines @@
 class CFWL_Widget;
 class CFWL_WidgetProperties;
 class CFWL_WidgetMgr;
 class IFWL_App;
 class IFWL_ThemeProvider;
 class IFWL_Widget;
 enum class FWL_Type;
 
 class IFWL_Widget : public IFWL_WidgetDelegate {
  public:
-  class DataProvider {
-   public:
-    virtual void GetCaption(IFWL_Widget* pWidget,
-                            CFX_WideString& wsCaption) = 0;
-  };
+  class DataProvider {};
 
   ~IFWL_Widget() override;
 
   virtual FWL_Type GetClassID() const = 0;
   virtual bool IsInstance(const CFX_WideStringC& wsClass) const;
   virtual void GetWidgetRect(CFX_RectF& rect, bool bAutoSize = false);
   virtual void GetClientRect(CFX_RectF& rect);
   virtual void ModifyStylesEx(uint32_t dwStylesExAdded,
                               uint32_t dwStylesExRemoved);
   virtual void SetStates(uint32_t dwStates, bool bSet = true);
@@ skipping 133 matching lines @@
   void NotifyDriver();
   bool IsParent(IFWL_Widget* pParent);
 
   void* m_pLayoutItem;
   CFWL_Widget* m_pAssociate;
   uint32_t m_nEventKey;
   IFWL_WidgetDelegate* m_pDelegate;  // Not owned.
 };
 
 #endif  // XFA_FWL_CORE_IFWL_WIDGET_H_