Convert XFA_ELEMENT to an enum class

xfa/fxfa/parser/cxfa_calculate.cpp

 // 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
 
 #include "xfa/fxfa/parser/cxfa_calculate.h"
 
 #include "xfa/fxfa/parser/cxfa_text.h"
 #include "xfa/fxfa/parser/xfa_object.h"
 
 CXFA_Calculate::CXFA_Calculate(CXFA_Node* pNode) : CXFA_Data(pNode) {}
 
 int32_t CXFA_Calculate::GetOverride() {
   XFA_ATTRIBUTEENUM eAtt = XFA_ATTRIBUTEENUM_Error;
   m_pNode->TryEnum(XFA_ATTRIBUTE_Override, eAtt, FALSE);
   return eAtt;
 }
 
 CXFA_Script CXFA_Calculate::GetScript() {
-  return CXFA_Script(m_pNode->GetChild(0, XFA_ELEMENT_Script));
+  return CXFA_Script(m_pNode->GetChild(0, XFA_Element::Script));
 }
 
 void CXFA_Calculate::GetMessageText(CFX_WideString& wsMessage) {
-  CXFA_Node* pNode = m_pNode->GetChild(0, XFA_ELEMENT_Message);
+  CXFA_Node* pNode = m_pNode->GetChild(0, XFA_Element::Message);
   if (!pNode)
     return;
 
-  CXFA_Text text(pNode->GetChild(0, XFA_ELEMENT_Text));
+  CXFA_Text text(pNode->GetChild(0, XFA_Element::Text));
   if (text)
     text.GetContent(wsMessage);
 }