[BackgroundSync] Remove BackgroundSyncRegistrationHandle

content/common/background_sync_service.mojom

 // Copyright 2015 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.
 
 module content;
 
 import "content/public/common/background_sync.mojom";
 import "content/public/common/service_worker_event_status.mojom";
 
 enum BackgroundSyncError {
@@ skipping 15 matching lines @@
   IS_NOT_LAST_CHANCE,
   IS_LAST_CHANCE
 };
 
 interface BackgroundSyncService {
   Register(SyncRegistration options, int64 service_worker_registration_id,
            bool requested_from_service_worker)
       => (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);
 };