Gracefully handle tests that print.

test/runner/browser/runner_test.dart

 // Copyright (c) 2015, 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.
 
 @TestOn("vm")
 
 import 'dart:io';
 
 import 'package:path/path.dart' as p;
 import 'package:unittest/src/util/exit_codes.dart' as exit_codes;
@@ skipping 139 matching lines @@
 void main() {
   test("test", () {
     if (p.style != p.Style.url) throw new TestFailure("oh no");
   });
 }
 """);
       var result = _runUnittest(["-p", "chrome", "-p", "vm", "test.dart"]);
       expect(result.exitCode, equals(1));
     });
   });
+
+  test("forwards prints from the browser test", () {
+    new File(p.join(_sandbox, "test.dart")).writeAsStringSync("""
+import 'dart:async';
+
+import 'package:unittest/unittest.dart';
+
+void main() {
+  test("test", () {
+    print("Hello,");
+    return new Future(() => print("world!"));
+  });
+}
+""");
+
+    var result = _runUnittest(["-p", "chrome", "test.dart"]);
+    expect(result.stdout, contains("Hello,\nworld!\n"));
+    expect(result.exitCode, equals(0));
+  });
 }
 
 ProcessResult _runUnittest(List<String> args) =>
     runUnittest(args, workingDirectory: _sandbox);