BackgroundSyncManager tracks client registrations

content/common/background_sync_service.mojom

Index: content/common/background_sync_service.mojom
diff --git a/content/common/background_sync_service.mojom b/content/common/background_sync_service.mojom
index c8299603689dd298bdbe6bc1fa3ae861dfa0106a..7f985f884162f9907d811959062954b9a0103a46 100644
--- a/content/common/background_sync_service.mojom
+++ b/content/common/background_sync_service.mojom
@@ -26,15 +26,19 @@ interface BackgroundSyncService {
   GetRegistrations(BackgroundSyncPeriodicity periodicity,
                    int64 service_worker_registration_id)
       => (BackgroundSyncError err, array<SyncRegistration> registrations);
-  Unregister(BackgroundSyncPeriodicity periodicity, int64 id, string tag,
+  Unregister(BackgroundSyncPeriodicity periodicity, int64 id,
              int64 service_worker_registration_id) => (BackgroundSyncError err);
   GetPermissionStatus(BackgroundSyncPeriodicity periodicity,
                       int64 service_worker_registration_id)
       => (BackgroundSyncError err, PermissionStatus status);
+  DuplicateRegistrationHandle(int64 handle_id,
+                              int64 service_worker_registration_id) 
+      => (BackgroundSyncError err, SyncRegistration? registration);  
+  ReleaseRegistration(int64 handle_id);
 };
 
 interface BackgroundSyncServiceClient {
-  Sync(SyncRegistration registration)
+  Sync(int64 handle_id)
       => (ServiceWorkerEventStatus status);
 };