Make down-conversion explicit from CFX_ByteString to CFX_ByteStringC.

core/fpdfapi/fpdf_font/fpdf_font.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/fpdfapi/fpdf_font/font_int.h"
 
 #include "core/fpdfapi/fpdf_page/include/cpdf_form.h"
 #include "core/fpdfapi/fpdf_page/pageint.h"
@@ skipping 215 matching lines @@
         }
       }
     } else if (word == "beginbfrange") {
       while (1) {
         CFX_ByteString low, high;
         low = parser.GetWord();
         if (low.IsEmpty() || low == "endbfrange") {
           break;
         }
         high = parser.GetWord();
-        uint32_t lowcode = StringToCode(low);
-        uint32_t highcode =
-            (lowcode & 0xffffff00) | (StringToCode(high) & 0xff);
+        uint32_t lowcode = StringToCode(low.AsByteStringC());
+        uint32_t highcode = (lowcode & 0xffffff00) |
+                            (StringToCode(high.AsByteStringC()) & 0xff);
         if (highcode == (uint32_t)-1) {
           break;
         }
         CFX_ByteString start = parser.GetWord();
         if (start == "[") {
           for (uint32_t code = lowcode; code <= highcode; code++) {
             CFX_ByteString dest = parser.GetWord();
-            CFX_WideString destcode = StringToWideString(dest);
+            CFX_WideString destcode = StringToWideString(dest.AsByteStringC());
             int len = destcode.GetLength();
             if (len == 0) {
               continue;
             }
             if (len == 1) {
               m_Map[code] = destcode.GetAt(0);
             } else {
               m_Map[code] = m_MultiCharBuf.GetLength() * 0x10000 + 0xffff;
               m_MultiCharBuf.AppendChar(destcode.GetLength());
               m_MultiCharBuf << destcode;
             }
           }
           parser.GetWord();
         } else {
-          CFX_WideString destcode = StringToWideString(start);
+          CFX_WideString destcode = StringToWideString(start.AsByteStringC());
           int len = destcode.GetLength();
           uint32_t value = 0;
           if (len == 1) {
-            value = StringToCode(start);
+            value = StringToCode(start.AsByteStringC());
             for (uint32_t code = lowcode; code <= highcode; code++) {
               m_Map[code] = value++;
             }
           } else {
             for (uint32_t code = lowcode; code <= highcode; code++) {
               CFX_WideString retcode;
               if (code == lowcode) {
                 retcode = destcode;
               } else {
                 retcode = StringDataAdd(destcode);
@@ skipping 18 matching lines @@
   }
   if (cid_set) {
     m_pBaseMap = CPDF_ModuleMgr::Get()
                      ->GetPageModule()
                      ->GetFontGlobals()
                      ->m_CMapManager.GetCID2UnicodeMap(cid_set, FALSE);
   } else {
     m_pBaseMap = NULL;
   }
 }