Add support for CSS unicod encoding to the text codec.

third_party/WebKit/Source/wtf/text/TextCodec.h

 /*
  * Copyright (C) 2004, 2006 Apple Computer, Inc.  All rights reserved.
  * Copyright (C) 2006 Alexey Proskuryakov <ap@nypop.com>
  *
  * 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
@@ skipping 32 matching lines @@
     // Substitutes the replacement character "?".
     QuestionMarksForUnencodables,
 
     // Encodes the character as an XML entity. For example, U+06DE
     // would be "&#1758;" (0x6DE = 1758 in octal).
     EntitiesForUnencodables,
 
     // Encodes the character as en entity as above, but escaped
     // non-alphanumeric characters. This is used in URLs.
     // For example, U+6DE would be "%26%231758%3B".
-    URLEncodedEntitiesForUnencodables
+    URLEncodedEntitiesForUnencodables,
+
+    // Encodes the character as a CSS entity.  For example U+06DE
+    // would be \06de.  See: https://www.w3.org/TR/css-syntax-3/#escaping
+    CSSEncodedEntitiesForUnencodables

[Łukasz Anforowicz, 2016/04/27 04:28:12]

nit: I read that C++11 allows a trailing comma in enum definitions.  Maybe we
could add that here to minimize future changes (and streamline git blame) if we
ever need to add more enum values.

[bburns, 2016/04/27 20:24:21]

Done.

 };
 
 typedef char UnencodableReplacementArray[32];
 
 enum FlushBehavior {
     // More bytes are coming, don't flush the codec.
     DoNotFlush = 0,
 
     // A fetch has hit EOF. Some codecs handle fetches differently, for compat reasons.
     FetchEOF,
@@ skipping 32 matching lines @@
 typedef void (*EncodingNameRegistrar)(const char* alias, const char* name);
 
 typedef PassOwnPtr<TextCodec> (*NewTextCodecFunction)(const TextEncoding&, const void* additionalData);
 typedef void (*TextCodecRegistrar)(const char* name, NewTextCodecFunction, const void* additionalData);
 
 } // namespace WTF
 
 using WTF::TextCodec;
 
 #endif // TextCodec_h