Pref service: create service at browser startup

components/sync_preferences/pref_service_syncable_factory.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef COMPONENTS_SYNC_PREFERENCES_PREF_SERVICE_SYNCABLE_FACTORY_H_
 #define COMPONENTS_SYNC_PREFERENCES_PREF_SERVICE_SYNCABLE_FACTORY_H_
 
 #include <memory>
 
 #include "base/macros.h"
 #include "components/prefs/pref_service_factory.h"
 
 namespace policy {
 class BrowserPolicyConnector;
 class PolicyService;
 }
 
+namespace service_manager {
+class Connector;
+}
+
 namespace user_prefs {
 class PrefRegistrySyncable;
 }
 
 namespace sync_preferences {
 
 class PrefModelAssociatorClient;
 class PrefServiceSyncable;
 
 // A PrefServiceFactory that also knows how to build a
 // PrefServiceSyncable, and may know about Chrome concepts such as
 // PolicyService.
 class PrefServiceSyncableFactory : public PrefServiceFactory {
  public:
   PrefServiceSyncableFactory();
   ~PrefServiceSyncableFactory() override;
 
   // Set up policy pref stores using the given policy service and connector.
   // These will assert when policy is not used.
   void SetManagedPolicies(policy::PolicyService* service,
                           policy::BrowserPolicyConnector* connector);
   void SetRecommendedPolicies(policy::PolicyService* service,
                               policy::BrowserPolicyConnector* connector);
 
   void SetPrefModelAssociatorClient(
       PrefModelAssociatorClient* pref_model_associator_client);
 
+  // |connector| might be null during test or if we're not using the Mojo pref
+  // |service.
   std::unique_ptr<PrefServiceSyncable> CreateSyncable(
-      user_prefs::PrefRegistrySyncable* registry);
+      user_prefs::PrefRegistrySyncable* registry,
+      service_manager::Connector* connector = nullptr);
 
  private:
   PrefModelAssociatorClient* pref_model_associator_client_;
 
   DISALLOW_COPY_AND_ASSIGN(PrefServiceSyncableFactory);
 };
 
 }  // namespace sync_preferences
 
 #endif  // COMPONENTS_SYNC_PREFERENCES_PREF_SERVICE_SYNCABLE_FACTORY_H_