Switch analysis_server to use 'package:test'.

pkg/analysis_server/test/integration/test_all.dart

Index: pkg/analysis_server/test/integration/test_all.dart
diff --git a/pkg/analysis_server/test/integration/test_all.dart b/pkg/analysis_server/test/integration/test_all.dart
index e217c925f73afc7f58a07d630137da902da34792..7ab4a7d952d13c51442f9a2e2708dc2dca7ff6e4 100644
--- a/pkg/analysis_server/test/integration/test_all.dart
+++ b/pkg/analysis_server/test/integration/test_all.dart
@@ -4,7 +4,7 @@
 
 library test.integration.all;
 
-import 'package:unittest/unittest.dart';
+import 'package:test_reflective_loader/test_reflective_loader.dart';
 
 import '../utils.dart';
 import 'analysis/test_all.dart' as analysis_test_all;
@@ -17,10 +17,10 @@ import 'server/test_all.dart' as server_test_all;
  */
 main() {
   initializeTestEnvironment();
-  group('analysis_server_integration', () {
+  defineReflectiveSuite(() {
     analysis_test_all.main();
     completion_test_all.main();
     search_test_all.main();
     server_test_all.main();
-  });
+  }, name: 'analysis_server_integration');
 }