[BackgroundSync] Remove BackgroundSyncRegistrationHandle

content/renderer/background_sync/background_sync_client_impl.h

 // 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.
 
 #ifndef CONTENT_RENDERER_BACKGROUND_SYNC_BACKGROUND_SYNC_CLIENT_IMPL_H_
 #define CONTENT_RENDERER_BACKGROUND_SYNC_BACKGROUND_SYNC_CLIENT_IMPL_H_
 
 #include <stdint.h>
 
 #include <map>
@@ skipping 13 matching lines @@
       mojo::InterfaceRequest<BackgroundSyncServiceClient> request);
 
   ~BackgroundSyncClientImpl() override;
 
  private:
   using SyncCallback = mojo::Callback<void(ServiceWorkerEventStatus)>;
   explicit BackgroundSyncClientImpl(
       mojo::InterfaceRequest<BackgroundSyncServiceClient> request);
 
   // BackgroundSyncServiceClient methods:
-  void Sync(int64_t handle_id,
+  void Sync(const mojo::String& tag,
             content::BackgroundSyncEventLastChance last_chance,
             const SyncCallback& callback) override;
-  void SyncDidGetRegistration(
-      int64_t callback_id,
-      content::BackgroundSyncEventLastChance last_chance,
-      BackgroundSyncError error,
-      SyncRegistrationPtr registration);
 
   mojo::StrongBinding<BackgroundSyncServiceClient> binding_;
 
-  int64_t callback_seq_num_;
-  std::map<int64_t, SyncCallback> sync_callbacks_;
-
   DISALLOW_COPY_AND_ASSIGN(BackgroundSyncClientImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_BACKGROUND_SYNC_BACKGROUND_SYNC_CLIENT_IMPL_H_