Convert CFXJSE_Value::ToString to return.

xfa/fxfa/app/xfa_ffwidgetacc.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/app/xfa_ffwidgetacc.h"
 
 #include <algorithm>
 #include <memory>
@@ skipping 640 matching lines @@
   FX_BOOL bRet = pContext->RunScript((XFA_SCRIPTLANGTYPE)eScriptType,
                                      wsExpression.AsStringC(),
                                      pTmpRetValue.get(), m_pNode);
   --m_nRecursionDepth;
   int32_t iRet = XFA_EVENTERROR_Error;
   if (bRet) {
     iRet = XFA_EVENTERROR_Success;
     if (pEventParam->m_eType == XFA_EVENT_Calculate ||
         pEventParam->m_eType == XFA_EVENT_InitCalculate) {
       if (!pTmpRetValue->IsUndefined()) {
-        if (!pTmpRetValue->IsNull()) {
-          CFX_ByteString bsString;
-          pTmpRetValue->ToString(bsString);
-          pEventParam->m_wsResult =
-              CFX_WideString::FromUTF8(bsString.AsStringC());
-        }
+        if (!pTmpRetValue->IsNull())
+          pEventParam->m_wsResult = pTmpRetValue->ToWideString();
+
         iRet = XFA_EVENTERROR_Success;
       } else {
         iRet = XFA_EVENTERROR_Error;
       }
       if (pEventParam->m_eType == XFA_EVENT_InitCalculate) {
         if ((iRet == XFA_EVENTERROR_Success) &&
             (GetRawValue() != pEventParam->m_wsResult)) {
           SetValue(pEventParam->m_wsResult, XFA_VALUEPICTURE_Raw);
           m_pDocView->AddValidateWidget(this);
         }
@@ skipping 1013 matching lines @@
     if (pIDNode) {
       pEmbAcc = (CXFA_WidgetAcc*)pIDNode->GetWidgetData();
     }
     if (pEmbAcc) {
       pEmbAcc->GetValue(wsValue, XFA_VALUEPICTURE_Display);
       return TRUE;
     }
   }
   return FALSE;
 }