Remove StreamSink(replaced by EventSink) and make IOSink extend EventSink.

sdk/lib/io/io_sink.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;
 
 /**
  * Helper class to wrap a [StreamConsumer<List<int>, T>] and provide
  * utility functions for writing to the StreamConsumer directly. The
  * [IOSink] buffers the input given by [write], [writeAll], [writeln],
- * [writeCharCode] and [writeBytes] and will delay a [consume] or
+ * [writeCharCode] and [add] and will delay a [consume] or
  * [writeStream] until the buffer is flushed.
  *
  * When the [IOSink] is bound to a stream (through either [consume]
  * or [writeStream]) any call to the [IOSink] will throw a
  * [StateError].
  */
-abstract class IOSink<T> implements StreamConsumer<List<int>, T>, StringSink {
+abstract class IOSink<T>
+    implements StreamConsumer<List<int>, T>, StringSink, EventSink<List<int>> {
   factory IOSink(StreamConsumer<List<int>, T> target,
                  {Encoding encoding: Encoding.UTF_8})
       => new _IOSinkImpl(target, encoding);
 
   /**
    * The [Encoding] used when writing strings. Depending on the
    * underlying consumer this property might be mutable.
    */
   Encoding encoding;
 
   /**
    * Writes the bytes uninterpreted to the consumer.
    */
-  void writeBytes(List<int> data);
+  void add(List<int> data);
+
+  /**
+   * Writes an error to the consumer.
+   */
+  void addError(AsyncError error);
 
   /**
    * Provide functionality for piping to the [IOSink].
    */
   Future<T> consume(Stream<List<int>> stream);
 
   /**
    * Adds all elements of the given [stream] to `this`.
    */
   Future<T> addStream(Stream<List<int>> stream);
@@ skipping 50 matching lines @@
     String string;
     if (obj is String) {
       string = obj;
     } else {
       string = obj.toString();
       if (string is! String) {
         throw new ArgumentError('toString() did not return a string');
       }
     }
     if (string.isEmpty) return;
-    writeBytes(_encodeString(string, _encoding));
+    add(_encodeString(string, _encoding));
   }
 
   void writeAll(Iterable objects, [String separator = ""]) {
     Iterator iterator = objects.iterator;
     if (!iterator.moveNext()) return;
     if (separator.isEmpty) {
       do {
         write(iterator.current);
       } while (iterator.moveNext());
     } else {
       write(iterator.current);
       while (iterator.moveNext()) {
         write(separator);
         write(iterator.current);
       }
     }
   }
 
   void writeln([Object obj = ""]) {
     write(obj);
     write("\n");
   }
 
   void writeCharCode(int charCode) {
     write(new String.fromCharCode(charCode));
   }
 
-  void writeBytes(List<int> data) {
+  void add(List<int> data) {
     if (_isBound) {
       throw new StateError("IOSink is already bound to a stream");
     }
     _controller.add(data);
   }
 
+  void addError(AsyncError error) {
+    if (_isBound) {
+      throw new StateError("IOSink is already bound to a stream");
+    }
+    _controller.addError(error);
+  }
+
   Future<T> consume(Stream<List<int>> stream) {
     if (_isBound) {
       throw new StateError("IOSink is already bound to a stream");
     }
     return _fillFromStream(stream);
   }
 
   Future<T> writeStream(Stream<List<int>> stream) {
     return addStream(stream);
   }
@@ skipping 103 matching lines @@
         },
         onError: _controller.addError);
     if (_paused) _pause();
     if (unbind) {
       return _writeStreamCompleter.future;
     } else {
       return _pipeFuture;
     }
   }
 }