Make CFX_ByteString(const CFX_ByteStringC&) explicit.

core/fxcrt/fx_basic_bstring.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 <stddef.h>
 
 #include <algorithm>
 #include <cctype>
@@ skipping 390 matching lines @@
       StringData::Create(m_pData->m_String + nCopyIndex, nCopyLen));
   dest.m_pData.Swap(pNewData);
 }
 
 #define FORCE_ANSI 0x10000
 #define FORCE_UNICODE 0x20000
 #define FORCE_INT64 0x40000
 
 CFX_ByteString CFX_ByteString::FormatInteger(int i, uint32_t flags) {
   char buf[32];
-  return CFX_ByteStringC(buf, Buffer_itoa(buf, i, flags));
+  return CFX_ByteString(buf, Buffer_itoa(buf, i, flags));
 }
 
 void CFX_ByteString::FormatV(const FX_CHAR* pFormat, va_list argList) {
   va_list argListSave;
 #if defined(__ARMCC_VERSION) ||                                              \
     (!defined(_MSC_VER) && (_FX_CPU_ == _FX_X64_ || _FX_CPU_ == _FX_IA64_ || \
                             _FX_CPU_ == _FX_ARM64_)) ||                      \
     defined(__native_client__)
   va_copy(argListSave, argList);
 #else
@@ skipping 554 matching lines @@
     fraction %= scale;
     scale /= 10;
   }
   return buf_size;
 }
 CFX_ByteString CFX_ByteString::FormatFloat(FX_FLOAT d, int precision) {
   FX_CHAR buf[32];
   FX_STRSIZE len = FX_ftoa(d, buf);
   return CFX_ByteString(buf, len);
 }