Make CFX_WideString(const CFX_WideString&) explicit.

xfa/fxfa/parser/xfa_locale.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/fxfa/parser/xfa_locale.h"
 
 #include "core/fxcrt/include/fx_xml.h"
 #include "xfa/fxfa/fm2js/xfa_fm2jsapi.h"
@@ skipping 208 matching lines @@
   }
 }
 CXFA_NodeLocale::CXFA_NodeLocale(CXFA_Node* pLocale) {
   m_pLocale = pLocale;
 }
 CXFA_NodeLocale::~CXFA_NodeLocale() {}
 void CXFA_NodeLocale::Release() {
   delete this;
 }
 CFX_WideString CXFA_NodeLocale::GetName() {
-  return m_pLocale ? m_pLocale->GetCData(XFA_ATTRIBUTE_Name) : NULL;
+  return CFX_WideString(m_pLocale ? m_pLocale->GetCData(XFA_ATTRIBUTE_Name)
+                                  : nullptr);
 }
 void CXFA_NodeLocale::GetNumbericSymbol(FX_LOCALENUMSYMBOL eType,
                                         CFX_WideString& wsNumSymbol) const {
   switch (eType) {
     case FX_LOCALENUMSYMBOL_Decimal:
       wsNumSymbol = GetSymbol(XFA_ELEMENT_NumberSymbols, FX_WSTRC(L"decimal"));
       break;
     case FX_LOCALENUMSYMBOL_Grouping:
       wsNumSymbol = GetSymbol(XFA_ELEMENT_NumberSymbols, FX_WSTRC(L"grouping"));
       break;
@@ skipping 125 matching lines @@
     CXFA_Node* pNode = pCalendar->GetFirstChildByClass(eElement);
     for (; pNode; pNode = pNode->GetNextSameClassSibling(eElement)) {
       if (pNode->GetBoolean(XFA_ATTRIBUTE_Abbr) == bAbbr) {
         CXFA_Node* pSymbol = pNode->GetChild(index, XFA_ELEMENT_UNKNOWN);
         return pSymbol ? pSymbol->GetContent() : CFX_WideString();
       }
     }
   }
   return CFX_WideString();
 }