Reapply revert of "Make stdout/stderr async"

sdk/lib/io/console.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;
-
-Console _console;
-
-Console get console {
-  if (_console == null) {
-    _console = new Console._();
-  }
-  return _console;
-}
-
-/**
- * [Console] provides synchronous write access to stdout and stderr.
- *
- * The direct access to stdout and stderr through [stdout] and [stderr]
- * provides non-blocking async operations.
- */
-class Console {
-  final ConsoleSink _stdout;
-  final ConsoleSink _stderr;
-
-  Console._()
-      : _stdout = new ConsoleSink._(1),
-        _stderr = new ConsoleSink._(2);
-
-  /**
-   * Write to stdout.
-   */
-  ConsoleSink get log => _stdout;
-
-  /**
-   * Write to stderr.
-   */
-  ConsoleSink get error => _stderr;
-}
-
-/**
- * Sink class used for console writing.
- *
- * This class has a call method so you can call it directly. Calling
- * it directly is the same as calling its `writeln` method.
- */
-class ConsoleSink implements Sink<List<int>>, StringSink {
-  IOSink _sink;
-
-  ConsoleSink._(int fd) {
-    _sink = new IOSink(new _ConsoleConsumer(fd));
-  }
-
-  void call([Object message = ""]) => _sink.writeln(message);
-
-  void add(List<int> data) => _sink.add(data);
-
-  void close() {}
-
-  void write(Object obj) => _sink.write(obj);
-
-  void writeAll(Iterable objects, [String separator=""]) =>
-      _sink.writeAll(objects, separator);
-
-  void writeCharCode(int charCode) => _sink.writeCharCode(charCode);
-
-  void writeln([Object obj=""]) => _sink.writeln(obj);
-}
-
-class _ConsoleConsumer implements StreamConsumer<List<int>> {
-  final _file;
-
-  _ConsoleConsumer(int fd) : _file = _File._openStdioSync(fd);
-
-  Future addStream(Stream<List<int>> stream) {
-    var completer = new Completer();
-    var sub;
-    sub = stream.listen(
-        (data) {
-          try {
-            _file.writeFromSync(data);
-          } catch (e, s) {
-            sub.cancel();
-            completer.completeError(e, s);
-          }
-        },
-        onError: completer.completeError,
-        onDone: completer.complete,
-        cancelOnError: true);
-    return completer.future;
-  }
-
-  Future close() {
-    _file.closeSync();
-    return new Future.value();
-  }
-}