Remove uses of unittest in the HTML tests where possible.

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

Index: pkg/dev_compiler/test/codegen/lib/html/storage_test.dart
diff --git a/pkg/dev_compiler/test/codegen/lib/html/storage_test.dart b/pkg/dev_compiler/test/codegen/lib/html/storage_test.dart
index b68e9d499b833bd401e65c3beea24f898ab16344..c614ca97ccd17c413dfccc45d36d7b3f297f81a6 100644
--- a/pkg/dev_compiler/test/codegen/lib/html/storage_test.dart
+++ b/pkg/dev_compiler/test/codegen/lib/html/storage_test.dart
@@ -1,10 +1,8 @@
-library StorageTest;
-import 'package:unittest/unittest.dart';
-import 'package:unittest/html_config.dart';
 import 'dart:html';
 
+import 'package:expect/minitest.dart';
+
 main() {
-  useHtmlConfiguration();
   test('GetItem', () {
     final value = window.localStorage['does not exist'];
     expect(value, isNull);