Prevent direct use of "replacement" text encoding.

Source/wtf/text/TextEncodingRegistry.h

 /*
  * Copyright (C) 2006, 2007 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 30 matching lines @@
 WTF_EXPORT PassOwnPtr<TextCodec> newTextCodec(const TextEncoding&);
 
 // Only TextEncoding should use the following functions directly.
 const char* atomicCanonicalTextEncodingName(const char* alias);
 template <typename CharacterType>
 const char* atomicCanonicalTextEncodingName(const CharacterType*, size_t);
 const char* atomicCanonicalTextEncodingName(const String&);
 bool noExtendedTextEncodingNameUsed();
 bool isJapaneseEncoding(const char* canonicalEncodingName);
 bool shouldShowBackslashAsCurrencySymbolIn(const char* canonicalEncodingName);
+bool isReplacementEncoding(const char* alias);
+bool isReplacementEncoding(const String& alias);
 
 #ifndef NDEBUG
 void dumpTextEncodingNameMap();
 #endif
 
 } // namespace WTF
 
 using WTF::newTextCodec;
 using WTF::atomicCanonicalTextEncodingName;
 using WTF::noExtendedTextEncodingNameUsed;
 using WTF::isJapaneseEncoding;
 using WTF::shouldShowBackslashAsCurrencySymbolIn;
 #ifndef NDEBUG
 using WTF::dumpTextEncodingNameMap;
 #endif
 
 #endif // TextEncodingRegistry_h