Add top-level driver and abstract plugin superclass

pkg/analyzer_plugin/test/utilities/test_all.dart

Index: pkg/analyzer_plugin/test/utilities/test_all.dart
diff --git a/pkg/analyzer_plugin/test/utilities/test_all.dart b/pkg/analyzer_plugin/test/utilities/test_all.dart
new file mode 100644
index 0000000000000000000000000000000000000000..0a87c37e4af363aa0b67497ae7a54441668fba1a
--- /dev/null
+++ b/pkg/analyzer_plugin/test/utilities/test_all.dart
@@ -0,0 +1,13 @@
+// Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import 'package:test_reflective_loader/test_reflective_loader.dart';
+
+import 'subscription_manager_test.dart' as subscription_manager_test;
+
+main() {
+  defineReflectiveSuite(() {
+    subscription_manager_test.main();
+  }, name: 'utilities');
+}