Add line handler to string stream

tests/standalone/src/StringStreamTest.dart

 // Copyright (c) 2011, 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.
 
 class ListInputStream implements InputStream {
   List<int> read() {
     var result = _data;
     _data = null;
     return result;
   }
@@ skipping 165 matching lines @@
       Expect.equals(null, line);
       Expect.equals(true, stream.closed);
       stage++;
     }
   }
 
   void streamClosed() {
     Expect.equals(4, stage);
   }
 
-  stream.dataHandler = stringData;
+  stream.lineHandler = stringData;
   stream.closeHandler = streamClosed;
   s.write("Line1\nLine2\r\nLine3\rLi".charCodes());
   Expect.equals(4, stage);
 }
 
 main() {
   testUtf8();
   testLatin1();
   testAscii();
   testReadLine1();
   testReadLine2();
 }