Rename String.concat to operator+.

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;
 
 /**
  * String encodings.
  */
 class Encoding {
@@ skipping 144 matching lines @@
 
 class LineTransformer extends StreamEventTransformer<String, String> {
   const int _LF = 10;
   const int _CR = 13;
 
   final StringBuffer _buffer = new StringBuffer();
   String _carry;
 
   void _handle(String data, StreamSink<String> sink, bool isClosing) {
     if (_carry != null) {
-      data = _carry.concat(data);
+      data = _carry + data;
       _carry = null;
     }
     int startPos = 0;
     int pos = 0;
     while (pos < data.length) {
       int skip = 0;
       int char = data.codeUnitAt(pos);
       if (char == _LF) {
         skip = 1;
       } else if (char == _CR) {
@@ skipping 130 matching lines @@
 
 // Utility class for decoding Windows current code page data delivered
 // as a stream of bytes.
 class _WindowsCodePageDecoder extends StreamEventTransformer<List<int>, String> {
   void handleData(List<int> data, StreamSink<String> sink) {
     sink.add(_decodeBytes(data));
   }
 
   external static String _decodeBytes(List<int> bytes);
 }