Implement "replacement" text encoding.

Source/modules/encoding/TextEncoder.cpp

 /*
  * Copyright (C) 2013 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 37 matching lines @@
         exceptionState.throwTypeError("The encoding label provided ('" + encodingLabel + "') is invalid.");
         return nullptr;
     }
 
     String name(encoding.name());
     if (name != "UTF-8" && name != "UTF-16LE" && name != "UTF-16BE") {
         exceptionState.throwTypeError("The encoding provided ('" + encodingLabel + "') is not one of 'utf-8', 'utf-16', or 'utf-16be'.");
         return nullptr;
     }
 
-    return adoptRefWillBeNoop(new TextEncoder(encoding.name()));
+    return adoptRefWillBeNoop(new TextEncoder(encodingLabel, name));
 }
 
-TextEncoder::TextEncoder(const String& encoding)
-    : m_encoding(encoding)
-    , m_codec(newTextCodec(m_encoding))
+TextEncoder::TextEncoder(const String& label, const String& name)
+    : m_encoding(name)
+    , m_codec(newTextCodec(label))
 {
 }
 
 TextEncoder::~TextEncoder()
 {
 }
 
 String TextEncoder::encoding() const
 {
-    String name = String(m_encoding.name()).lower();
+    String name = m_encoding.lower();
     ASSERT(name == "utf-8" || name == "utf-16le" || name == "utf-16be");
     return name;
 }
 
 PassRefPtr<Uint8Array> TextEncoder::encode(const String& input, const Dictionary& options)
 {
     bool stream = false;
     options.get("stream", stream);
 
     // FIXME: Not flushing is not supported by TextCodec for encode; add it or
     // handle split surrogates here.
 
     CString result;
     if (input.is8Bit())
         result = m_codec->encode(input.characters8(), input.length(), WTF::QuestionMarksForUnencodables);
     else
         result = m_codec->encode(input.characters16(), input.length(), WTF::QuestionMarksForUnencodables);
 
     const char* buffer = result.data();
     const unsigned char* unsignedBuffer = reinterpret_cast<const unsigned char*>(buffer);
 
     return Uint8Array::create(unsignedBuffer, result.length());
 }
 
 } // namespace WebCore