Make down-conversion explicit from CFX_Widetring to CFX_WideStringC.

xfa/fgas/font/fgas_stdfontmgr.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/fgas/font/fgas_stdfontmgr.h"
 
 #include "core/fxcrt/include/fx_stream.h"
 #include "xfa/fgas/crt/fgas_codepage.h"
@@ skipping 543 matching lines @@
 }
 FX_POSITION CFX_FontSourceEnum_File::GetStartPosition(void* pUserData) {
   m_wsNext = GetNextFile().UTF8Decode();
   if (0 == m_wsNext.GetLength()) {
     return (FX_POSITION)0;
   }
   return (FX_POSITION)-1;
 }
 IFX_FileAccess* CFX_FontSourceEnum_File::GetNext(FX_POSITION& pos,
                                                  void* pUserData) {
-  IFX_FileAccess* pAccess = FX_CreateDefaultFileAccess(m_wsNext);
+  IFX_FileAccess* pAccess =
+      FX_CreateDefaultFileAccess(m_wsNext.AsWideStringC());
   m_wsNext = GetNextFile().UTF8Decode();
   pos = 0 != m_wsNext.GetLength() ? pAccess : NULL;
   return (IFX_FileAccess*)pAccess;
 }
 IFX_FontSourceEnum* FX_CreateDefaultFontSourceEnum() {
   return (IFX_FontSourceEnum*)new CFX_FontSourceEnum_File;
 }
 IFX_FontMgr* IFX_FontMgr::Create(IFX_FontSourceEnum* pFontEnum,
                                  IFX_FontMgrDelegate* pDelegate,
                                  void* pUserData) {
@@ skipping 932 matching lines @@
   }
 }
 int32_t CFX_FontMgrImp::IsPartName(const CFX_WideString& Name1,
                                    const CFX_WideString& Name2) {
   if (Name1.Find((const FX_WCHAR*)Name2) != -1) {
     return 1;
   }
   return 0;
 }
 #endif