Convert XFA_ELEMENT to an enum class

xfa/fxfa/parser/cxfa_data.h

 // Copyright 2016 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_FXFA_PARSER_CXFA_DATA_H_
 #define XFA_FXFA_PARSER_CXFA_DATA_H_
 
 #include "core/fxcrt/include/fx_system.h"
 #include "core/fxge/include/fx_dib.h"
 #include "xfa/fxfa/include/fxfa_basic.h"
 
 class CXFA_Node;
 
 class CXFA_Data {
  public:
   static FX_ARGB ToColor(const CFX_WideStringC& wsValue);
 
   explicit CXFA_Data(CXFA_Node* pNode) : m_pNode(pNode) {}
 
   operator bool() const { return !!m_pNode; }
   CXFA_Node* GetNode() const { return m_pNode; }
-  XFA_ELEMENT GetClassID() const;
+  XFA_Element GetClassID() const;
 
  protected:
   FX_BOOL TryMeasure(XFA_ATTRIBUTE eAttr,
                      FX_FLOAT& fValue,
                      FX_BOOL bUseDefault = FALSE) const;
   FX_BOOL SetMeasure(XFA_ATTRIBUTE eAttr, FX_FLOAT fValue);
 
   CXFA_Node* m_pNode;
 };
 
 #endif  // XFA_FXFA_PARSER_CXFA_DATA_H_