Remove implicit cast from CFX_ByteString to (const char*).

xfa/fgas/crt/fgas_codepage.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 "core/fxcrt/include/fx_ext.h"
 #include "xfa/fgas/crt/fgas_codepage.h"
 #include "xfa/fgas/crt/fgas_language.h"
 
@@ skipping 321 matching lines @@
   }
   if (iLength == 0) {
     return 0xFFFF;
   }
   CFX_ByteString csStr;
   FX_CHAR* pBuf = csStr.GetBuffer(iLength + 1);
   for (int32_t i = 0; i < iLength; ++i) {
     *pBuf++ = (FX_CHAR)*pStr++;
   }
   csStr.ReleaseBuffer(iLength);
-  return FX_GetCodePageFromStringA(csStr, iLength);
+  return FX_GetCodePageFromStringA(csStr.c_str(), iLength);
 }