Make convert library strong-mode compliant.

sdk/lib/convert/line_splitter.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.convert;
 
 // Character constants.
 const int _LF = 10;
 const int _CR = 13;
 
 /**
  * A [Converter] that splits a [String] into individual lines.
  *
  * A line is terminated by either a CR (U+000D), a LF (U+000A), a
  * CR+LF sequence (DOS line ending),
  * and a final non-empty line can be ended by the end of the string.
  *
  * The returned lines do not contain the line terminators.
  */
-class LineSplitter extends Converter<String, List<String>> {
+class LineSplitter extends
+    ChunkedConverter<String, List<String>, String, String> {
 
   const LineSplitter();
 
   /// Split [lines] into individual lines.
   ///
   /// If [start] and [end] are provided, only split the contents of
   /// `lines.substring(start, end)`. The [start] and [end] values must
   /// specify a valid sub-range of [lines]
   /// (`0 <= start <= end <= lines.length`).
   static Iterable<String> split(String lines, [int start = 0, int end]) sync* {
@@ skipping 41 matching lines @@
     }
     return lines;
   }
 
   StringConversionSink startChunkedConversion(Sink<String> sink) {
     if (sink is! StringConversionSink) {
       sink = new StringConversionSink.from(sink);
     }
     return new _LineSplitterSink(sink);
   }
-
-  // Override the base-class' bind, to provide a better type.
-  Stream<String> bind(Stream<String> stream) => super.bind(stream);
 }
 
 // TODO(floitsch): deal with utf8.
 class _LineSplitterSink extends StringConversionSinkBase {
   final StringConversionSink _sink;
 
   /// The carry-over from the previous chunk.
   ///
   /// If the previous slice ended in a line without a line terminator,
   /// then the next slice may continue the line.
@@ skipping 57 matching lines @@
       _sink.add(lines.substring(sliceStart, i));
       sliceStart = i + 1;
     }
     if (sliceStart < end) {
       _carry = lines.substring(sliceStart, end);
     } else {
       _skipLeadingLF = (char == _CR);
     }
   }
 }