[BackgroundSync] Remove BackgroundSyncRegistrationHandle

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 8ff823c8d3c32bc2907dcd4df7d36b5c87c6df2c..3d7731e67ea796290d1001e174a4c75ef153f3c5 100644
--- a/content/common/background_sync_service.mojom
+++ b/content/common/background_sync_service.mojom
@@ -33,13 +33,10 @@ interface BackgroundSyncService {
       => (BackgroundSyncError err, SyncRegistration options);
   GetRegistrations(int64 service_worker_registration_id)
       => (BackgroundSyncError err, array<SyncRegistration> registrations);
-  DuplicateRegistrationHandle(int64 handle_id)
-      => (BackgroundSyncError err, SyncRegistration? registration);
-  ReleaseRegistration(int64 handle_id);
 };
 
 interface BackgroundSyncServiceClient {
-  Sync(int64 handle_id, BackgroundSyncEventLastChance last_chance)
+  Sync(string tag, BackgroundSyncEventLastChance last_chance)
       => (ServiceWorkerEventStatus status);
 };