Update the streams interfaces

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 InputStream2 {
+  List<int> read() {
+    var result = _data;
+    _data = null;
+    return result;
+  }
+
+  void set dataHandler(void callback()) {
+    _datahandler = callback;
+  }
+
+  void set closeHandler(void callback()) {
+  }
+
+  void set errorHandler(void callback(int error)) {
+  }
+
+  write(List<int> data) {
+    Expect.equals(null, _data);
+    _data = data;
+    if (_datahandler != null) {
+      _datahandler();
+    }
+  }
+
+  List<int> _data;
+  var _datahandler;
+}
+
+
+main() {
+  List<int> data = [0x01,
+                    0x7f,
+                    0xc2, 0x80,
+                    0xdf, 0xbf,
+                    0xe0, 0xa0, 0x80,
+                    0xef, 0xbf, 0xbf];
+  InputStream2 s = new ListInputStream();
+  StringInputStream stream = new StringInputStream(s);
+  void stringData() {
+    String s = stream.read();
+    Expect.equals(6, s.length);
+    Expect.equals(new String.fromCharCodes([0x01]), s[0]);
+    Expect.equals(new String.fromCharCodes([0x7f]), s[1]);
+    Expect.equals(new String.fromCharCodes([0x80]), s[2]);
+    Expect.equals(new String.fromCharCodes([0x7ff]), s[3]);
+    Expect.equals(new String.fromCharCodes([0x800]), s[4]);
+    Expect.equals(new String.fromCharCodes([0xffff]), s[5]);
+  }
+  stream.dataHandler = stringData;
+  s.write(data);
+}