[Merge to M53]arc: Enable user control for Arc package sync.

components/sync_driver/sync_prefs_unittest.cc

Index: components/sync_driver/sync_prefs_unittest.cc
diff --git a/components/sync_driver/sync_prefs_unittest.cc b/components/sync_driver/sync_prefs_unittest.cc
index 88ff2ebab728e898f0236aed014b6206247ecdc9..62ed5752bdc29a18766be85c3649795d39b1ec54 100644
--- a/components/sync_driver/sync_prefs_unittest.cc
+++ b/components/sync_driver/sync_prefs_unittest.cc
@@ -155,6 +155,7 @@ TEST_F(SyncPrefsTest, PreferredTypesNotKeepEverythingSynced) {
       expected_preferred_types.Put(syncer::APP_LIST);
       expected_preferred_types.Put(syncer::APP_NOTIFICATIONS);
       expected_preferred_types.Put(syncer::APP_SETTINGS);
+      expected_preferred_types.Put(syncer::ARC_PACKAGE);
     }
     if (it.Get() == syncer::EXTENSIONS) {
       expected_preferred_types.Put(syncer::EXTENSION_SETTINGS);