Remove uses of unittest in the HTML tests where possible.

pkg/dev_compiler/test/codegen/lib/html/rtc_test.dart

Index: pkg/dev_compiler/test/codegen/lib/html/rtc_test.dart
diff --git a/pkg/dev_compiler/test/codegen/lib/html/rtc_test.dart b/pkg/dev_compiler/test/codegen/lib/html/rtc_test.dart
index e55e79ff0f1f8375308a36b496d36396b686c0cd..8582b3a4cea28fc0c955af6cfaa51ff775f51518 100644
--- a/pkg/dev_compiler/test/codegen/lib/html/rtc_test.dart
+++ b/pkg/dev_compiler/test/codegen/lib/html/rtc_test.dart
@@ -2,17 +2,14 @@
 // 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.
 
-library RealTimeCommunicationTest;
-import 'package:unittest/unittest.dart';
-import 'package:unittest/html_individual_config.dart';
 import 'dart:html';
 
-main() {
-  useHtmlIndividualConfiguration();
+import 'package:expect/minitest.dart';
 
+main() {
   group('supported', () {
     test('supported', () {
-      expect(RtcPeerConnection.supported, true);
+      expect(RtcPeerConnection.supported, isTrue);
     });
   });