Pref service: Merge connectors and send a PrefRegistry in Connect().

components/sync_preferences/pref_service_syncable_factory.cc

Index: components/sync_preferences/pref_service_syncable_factory.cc
diff --git a/components/sync_preferences/pref_service_syncable_factory.cc b/components/sync_preferences/pref_service_syncable_factory.cc
index 9e5989aa0a25a3ab6c66017eed0e5127e28669f4..ba3f40fd7b86273383395b1aef9cc5e0c9176725 100644
--- a/components/sync_preferences/pref_service_syncable_factory.cc
+++ b/components/sync_preferences/pref_service_syncable_factory.cc
@@ -11,6 +11,7 @@
 #include "components/prefs/pref_notifier_impl.h"
 #include "components/prefs/pref_value_store.h"
 #include "components/sync_preferences/pref_service_syncable.h"
+#include "services/preferences/public/cpp/persistent_pref_store_client.h"
 #include "services/preferences/public/cpp/pref_store_adapter.h"
 #include "services/preferences/public/interfaces/preferences.mojom.h"
 #include "services/service_manager/public/cpp/connector.h"
@@ -83,6 +84,14 @@ std::unique_ptr<PrefServiceSyncable> PrefServiceSyncableFactory::CreateSyncable(
   TRACE_EVENT0("browser", "PrefServiceSyncableFactory::CreateSyncable");
   PrefNotifierImpl* pref_notifier = new PrefNotifierImpl();
 
+  if (!user_prefs_) {
+    prefs::mojom::PrefStoreConnectorPtr pref_connector;
+    connector->BindInterface(prefs::mojom::kPrefStoreServiceName,
+                             &pref_connector);
+    user_prefs_ = new prefs::PersistentPrefStoreClient(
+        std::move(pref_connector), make_scoped_refptr(pref_registry));
+  }
+
   // Expose all read-only stores through the prefs service.
   auto managed = CreateRegisteredPrefStore(connector, managed_prefs_,
                                            PrefValueStore::MANAGED_STORE);