Switch analysis_server to use 'package:test'.

pkg/analysis_server/test/plugin/set_analysis_domain_test.dart

Index: pkg/analysis_server/test/plugin/set_analysis_domain_test.dart
diff --git a/pkg/analysis_server/test/plugin/set_analysis_domain_test.dart b/pkg/analysis_server/test/plugin/set_analysis_domain_test.dart
index 36e152241146ea24b332e0a75d274a3aeef5c4da..70d238dd079daf43ed489e92d544fa1e38890adf 100644
--- a/pkg/analysis_server/test/plugin/set_analysis_domain_test.dart
+++ b/pkg/analysis_server/test/plugin/set_analysis_domain_test.dart
@@ -17,15 +17,17 @@ import 'package:analyzer/src/generated/engine.dart';
 import 'package:analyzer/src/generated/source.dart';
 import 'package:analyzer/task/dart.dart';
 import 'package:plugin/plugin.dart';
+import 'package:test/test.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
-import 'package:unittest/unittest.dart';
 
 import '../analysis_abstract.dart';
 import '../utils.dart';
 
 main() {
   initializeTestEnvironment();
-  defineReflectiveTests(SetAnalysisDomainTest);
+  defineReflectiveSuite(() {
+    defineReflectiveTests(SetAnalysisDomainTest);
+  });
 }
 
 /**