Add Stdio.readByteSync and Stdio.readLineSync.

tests/standalone/io/stdin_sync_test.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.
+
+import "dart:io";
+import "dart:json";
+
+void test(String line, List<String> expected) {
+  var script = new Path(Platform.script).directoryPath;
+  script = script.append("stdin_sync_script.dart");
+  Process.start(Platform.executable,
+                [script.toNativePath()]..addAll(
+                    expected.map(stringify))).then((process) {
+    process.stdin.write(line);
+    process.stdin.close();
+    process.stderr
+        .transform(new StringDecoder())
+        .transform(new LineTransformer())
+        .fold(new StringBuffer(), (b, d) => b..write(d))
+        .then((data) {
+          if (data.toString() != '') throw "Bad output: '$data'";
+        });
+    process.stdout
+        .transform(new StringDecoder())
+        .transform(new LineTransformer())
+        .fold(new StringBuffer(), (b, d) => b..write(d))
+        .then((data) {
+//          if (data.toString() != 'true') throw "Bad output: '$data'";
+        });
+  });
+}
+
+void main() {
+  test("hej\x01\x00\x0d\x0a\x0a4\x0a", ['hej\x01\x00', '', '4']);
+
+  test("hej\xFF\x00", ['hej\xFF\x00']);

[Bill Hesse, 2013/07/02 13:08:27]

This should fail on Windows, since you are writing with a UTF-8 encoding and
reading with a Windows code page.  At least this is what it looks like to me
(Encoding.UTF_8 on process.stdin.write and Encoding.SYSTEM on readLineSync. 
That raises the question of what encoding is happening to arguments in
Process.start.  Maybe not just \xFF but \u01234 should be tried.

[Anders Johnsen, 2013/07/02 13:17:15]

Done.

+
+  test("hej\rhej\nhej\r", ['hej\rhej', 'hej\r']);
+

[Bill Hesse, 2013/07/02 13:08:27]

"hej\r\r\nhej\r\rhej\n"

[Anders Johnsen, 2013/07/02 13:17:15]

Done.

+  test("hej", ['hej']);
+}