Enable MacOSX native notifications by default

chrome/browser/extensions/service_worker_apitest.cc

Index: chrome/browser/extensions/service_worker_apitest.cc
diff --git a/chrome/browser/extensions/service_worker_apitest.cc b/chrome/browser/extensions/service_worker_apitest.cc
index 639e6249345f09c63bb311e844eeb2ec5021d98e..80336ceec993b44de96278c1323a670ec9e0f508 100644
--- a/chrome/browser/extensions/service_worker_apitest.cc
+++ b/chrome/browser/extensions/service_worker_apitest.cc
@@ -13,6 +13,8 @@
 #include "chrome/browser/gcm/fake_gcm_profile_service.h"
 #include "chrome/browser/gcm/gcm_profile_service_factory.h"
 #include "chrome/browser/notifications/desktop_notification_profile_util.h"
+#include "chrome/browser/notifications/notification_display_service_factory.h"
+#include "chrome/browser/notifications/stub_notification_display_service.h"
 #include "chrome/browser/permissions/permission_manager.h"
 #include "chrome/browser/permissions/permission_result.h"
 #include "chrome/browser/push_messaging/push_messaging_app_identifier.h"
@@ -249,6 +251,9 @@ class ServiceWorkerPushMessagingTest : public ServiceWorkerTest {
     ServiceWorkerTest::SetUpCommandLine(command_line);
   }
   void SetUpOnMainThread() override {
+    NotificationDisplayServiceFactory::GetInstance()->SetTestingFactory(
+        profile(), &StubNotificationDisplayService::FactoryForTests);
+
     gcm::FakeGCMProfileService* gcm_service =
         static_cast<gcm::FakeGCMProfileService*>(
             gcm::GCMProfileServiceFactory::GetInstance()