Switch analysis_server to use 'package:test'.

pkg/analysis_server/test/services/completion/dart/test_all.dart

Index: pkg/analysis_server/test/services/completion/dart/test_all.dart
diff --git a/pkg/analysis_server/test/services/completion/dart/test_all.dart b/pkg/analysis_server/test/services/completion/dart/test_all.dart
index e9fb6c5f724bf3f990cbebb38b05276e331df26a..0493001289cc7829ead5477ddb045fe11af0bfb7 100644
--- a/pkg/analysis_server/test/services/completion/dart/test_all.dart
+++ b/pkg/analysis_server/test/services/completion/dart/test_all.dart
@@ -4,7 +4,7 @@
 
 library test.services.completion.dart;
 
-import 'package:unittest/unittest.dart';
+import 'package:test_reflective_loader/test_reflective_loader.dart';
 
 import '../../../utils.dart';
 import 'arglist_contributor_test.dart' as arglist_test;
@@ -33,7 +33,7 @@ import 'variable_name_contributor_test.dart' as variable_name_contributor_test;
 /// Utility for manually running all tests.
 main() {
   initializeTestEnvironment();
-  group('dart/completion', () {
+  defineReflectiveSuite(() {
     arglist_test.main();
     combinator_test.main();
     common_usage_test.main();
@@ -56,5 +56,5 @@ main() {
     type_member_contributor_test.main();
     uri_contributor_test.main();
     variable_name_contributor_test.main();
-  });
+  }, name: 'dart');
 }