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

core/fpdfapi/fpdf_font/cpdf_font.cpp

 // Copyright 2016 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/fpdfapi/fpdf_font/include/cpdf_font.h"
 
 #include "core/fpdfapi/fpdf_font/cpdf_truetypefont.h"
 #include "core/fpdfapi/fpdf_font/cpdf_type1font.h"
@@ skipping 467 matching lines @@
 
 const FX_CHAR* CPDF_Font::GetAdobeCharName(int iBaseEncoding,
                                            const CFX_ByteString* pCharNames,
                                            int charcode) {
   ASSERT(charcode >= 0 && charcode < 256);
   if (charcode < 0 || charcode >= 256)
     return nullptr;
 
   const FX_CHAR* name = nullptr;
   if (pCharNames)
-    name = pCharNames[charcode];
+    name = pCharNames[charcode].c_str();
   if ((!name || name[0] == 0) && iBaseEncoding)
     name = PDF_CharNameFromPredefinedCharSet(iBaseEncoding, charcode);
   return name && name[0] ? name : nullptr;
 }