Add IE support.

lib/src/runner/browser/server.dart

Index: lib/src/runner/browser/server.dart
diff --git a/lib/src/runner/browser/server.dart b/lib/src/runner/browser/server.dart
index 06c97668e5256b71053e22af1155edf2aef3ee5d..5fbbf8ad35951ac545bd2d24d1ac7c1c29ee85e9 100644
--- a/lib/src/runner/browser/server.dart
+++ b/lib/src/runner/browser/server.dart
@@ -28,9 +28,10 @@ import 'browser.dart';
 import 'browser_manager.dart';
 import 'compiler_pool.dart';
 import 'chrome.dart';
-import 'dartium.dart';
 import 'content_shell.dart';
+import 'dartium.dart';
 import 'firefox.dart';
+import 'internet_explorer.dart';
 import 'phantom_js.dart';
 import 'safari.dart';
 
@@ -389,6 +390,7 @@ void main() {
       case TestPlatform.phantomJS: return new PhantomJS(url);
       case TestPlatform.firefox: return new Firefox(url);
       case TestPlatform.safari: return new Safari(url);
+      case TestPlatform.internetExplorer: return new InternetExplorer(url);
       default:
         throw new ArgumentError("$browser is not a browser.");
     }