Remove uses of unittest in the HTML tests where possible.

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

Index: pkg/dev_compiler/test/codegen/lib/html/performance_api_test.dart
diff --git a/pkg/dev_compiler/test/codegen/lib/html/performance_api_test.dart b/pkg/dev_compiler/test/codegen/lib/html/performance_api_test.dart
index f4f1d287daa703e5482a1f46ebdadf02701b7bb4..b66feeb15c13fdfdfdf0f4f94b825a076ee318e6 100644
--- a/pkg/dev_compiler/test/codegen/lib/html/performance_api_test.dart
+++ b/pkg/dev_compiler/test/codegen/lib/html/performance_api_test.dart
@@ -1,11 +1,8 @@
-library PerformanceApiTest;
-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(Performance.supported, true);