Enable strict flags for all service tests

runtime/observatory/test/test_helper.dart

Index: runtime/observatory/test/test_helper.dart
diff --git a/runtime/observatory/test/test_helper.dart b/runtime/observatory/test/test_helper.dart
index aa3c2a0db41cd66f65213dc24612832f3ae63013..f26d2f7796ff1bf4fd478e8f1ad417baa76109d9 100644
--- a/runtime/observatory/test/test_helper.dart
+++ b/runtime/observatory/test/test_helper.dart
@@ -1,6 +1,7 @@
 // Copyright (c) 2013, 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.
+// VMOptions=--compile-all --error_on_bad_type --error_on_bad_override --checked
 
 library test_helper;