Fix sdk/lib/io errors found by the analyzer.

sdk/lib/io/string_transformer.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 part of dart.io;
 
 const SYSTEM_ENCODING = const SystemEncoding();
 
 /**
  * The system encoding is the current code page on Windows and UTF-8 on
  * Linux and Mac.
  */
 class SystemEncoding extends Encoding {
   const SystemEncoding();
 
+  String get name => 'system';
+
   List<int> encode(String input) => encoder.convert(input);
   String decode(List<int> encoded) => decoder.convert(encoded);
 
   Converter<String, List<int>> get encoder {
     if (Platform.operatingSystem == "windows") {
       return const _WindowsCodePageEncoder();
     } else {
       return const Utf8Encoder();
     }
   }
@@ skipping 94 matching lines @@
   _WindowsCodePageDecoderSink(this._sink);
 
   void close() {
     _sink.close();
   }
 
   void add(List<int> bytes) {
     _sink.add(_WindowsCodePageDecoder._decodeBytes(bytes));
   }
 }