Add IE support.

test/runner/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 'dart:math' as math;
 
 import 'package:path/path.dart' as p;
@@ skipping 22 matching lines @@
 
 void main() {
   test("failure", () => throw new TestFailure("oh no"));
 }
 """;
 
 final _defaultConcurrency = math.max(1, Platform.numberOfProcessors ~/ 2);
 
 final _browsers =
     "[vm (default), dartium, content-shell, chrome, phantomjs, firefox" +
-        (Platform.isMacOS ? ", safari" : "") + "]";
+        (Platform.isMacOS ? ", safari" : "") +
+        (Platform.isWindows ? ", ie" : "") + "]";
 
 final _usage = """
 Usage: pub run test:test [files or directories...]
 
 -h, --help                     Shows this usage information.
     --version                  Shows the package's version.
 -n, --name                     A substring of the name of the test to run.
                                Regular expression syntax is supported.
 
 -N, --plain-name               A plain-text substring of the name of the test to run.
@@ skipping 605 matching lines @@
       });
     });
   });
 }
 
 ProcessResult _runTest(List<String> args) =>
     runTest(args, workingDirectory: _sandbox);
 
 ProcessResult _runDart(List<String> args) =>
     runDart(args, workingDirectory: _sandbox);