Implement "replacement" text encoding.

Source/wtf/text/TextEncodingRegistry.cpp

Index: Source/wtf/text/TextEncodingRegistry.cpp
diff --git a/Source/wtf/text/TextEncodingRegistry.cpp b/Source/wtf/text/TextEncodingRegistry.cpp
index 4dd0240043c598532f930409e545dd1a3848e671..3b276dd8b2e98d30f6a4ce707a807aa7ac56881c 100644
--- a/Source/wtf/text/TextEncodingRegistry.cpp
+++ b/Source/wtf/text/TextEncodingRegistry.cpp
@@ -38,6 +38,7 @@
 #include "wtf/text/CString.h"
 #include "wtf/text/TextCodecICU.h"
 #include "wtf/text/TextCodecLatin1.h"
+#include "wtf/text/TextCodecReplacement.h"
 #include "wtf/text/TextCodecUTF16.h"
 #include "wtf/text/TextCodecUTF8.h"
 #include "wtf/text/TextCodecUserDefined.h"
@@ -220,6 +221,10 @@ static void buildBaseTextCodecMaps()
 
     TextCodecUserDefined::registerEncodingNames(addToTextEncodingNameMap);
     TextCodecUserDefined::registerCodecs(addToTextCodecMap);
+
+    TextCodecReplacement::registerEncodingNames(addToTextEncodingNameMap);
+    TextCodecReplacement::registerCodecs(addToTextCodecMap);
+    textEncodingNameMap->remove("replacement");

[jsbell, 2014/02/21 22:35:55]

This seems like a hack, but so far as I can tell the alternatives are either
special-casing "replacement" in various entry points so it can't be referenced
by name, or touching all of the places in this file that assert that a codec
have itself as a label.

 }
 
 static void addEncodingName(HashSet<const char*>* set, const char* name)