Make down-conversion explicit from CFX_Widetring to CFX_WideStringC.

xfa/fwl/core/fwl_formimp.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/fwl/core/fwl_formimp.h"
 
 #include "xfa/fde/tto/fde_textout.h"
 #include "xfa/fwl/basewidget/fwl_formproxyimp.h"
@@ skipping 804 matching lines @@
 void CFWL_FormImp::UpdateCaption() {
   CFWL_WidgetMgr* pWidgetMgr = static_cast<CFWL_WidgetMgr*>(FWL_GetWidgetMgr());
   if (!pWidgetMgr)
     return;
   IFWL_FormDP* pData =
       static_cast<IFWL_FormDP*>(m_pProperties->m_pDataProvider);
   if (!pData)
     return;
   CFX_WideString text;
   pData->GetCaption(m_pInterface, text);
-  pWidgetMgr->SetWidgetCaption_Native(m_pInterface, text);
+  pWidgetMgr->SetWidgetCaption_Native(m_pInterface, text.AsWideStringC());
 }
 void CFWL_FormImp::DoWidthLimit(FX_FLOAT& fLeft,
                                 FX_FLOAT& fWidth,
                                 FX_FLOAT fCurX,
                                 FX_FLOAT fSpace,
                                 FX_FLOAT fLimitMin,
                                 FX_FLOAT fLimitMax,
                                 FX_BOOL bLeft) {
   FX_FLOAT fx = fCurX;
   FX_FLOAT fy = 0;
@@ skipping 334 matching lines @@
   eClose.m_pSrcTarget = m_pOwner->m_pInterface;
   m_pOwner->DispatchEvent(&eClose);
 }
 FWL_ERR FWL_Accelerator_SetForm(IFWL_Form* pFrom,
                                 CFX_MapAccelerators* pMapAccel) {
   CFWL_FormImp* pImp = static_cast<CFWL_FormImp*>(pFrom->GetImpl());
   if (!pImp)
     return FWL_ERR_Indefinite;
   return FWL_ERR_Succeeded;
 }