Fix race in service/logging_test.

runtime/observatory/tests/service/logging_test.dart

Index: runtime/observatory/tests/service/logging_test.dart
diff --git a/runtime/observatory/tests/service/logging_test.dart b/runtime/observatory/tests/service/logging_test.dart
index cefa67bc1ab142952571765c7e2f471d020c2cc3..b8839f11b85af3c6aa7b5f92b06b142e2b04bdd7 100644
--- a/runtime/observatory/tests/service/logging_test.dart
+++ b/runtime/observatory/tests/service/logging_test.dart
@@ -40,6 +40,7 @@ var tests = [
     expect(event.logRecord['level'], equals(Level.FINE));
     expect(event.logRecord['time'], new isInstanceOf<DateTime>());
   }),
+  hasStoppedAtBreakpoint,
   resumeIsolateAndAwaitEvent(Isolate.kLoggingStream, (ServiceEvent event) {
     expect(event.kind, equals(ServiceEvent.kLogging));
     expect(event.logRecord['sequenceNumber'], equals(1));