[Background Sync] Add proper error status to API calls and callbacks

content/child/background_sync/background_sync_provider.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_CHILD_BACKGROUND_SYNC_BACKGROUND_SYNC_PROVIDER_H_
 #define CONTENT_CHILD_BACKGROUND_SYNC_BACKGROUND_SYNC_PROVIDER_H_
 
 #include <string>
 
 #include "base/memory/scoped_ptr.h"
@@ skipping 34 matching lines @@
       blink::WebSyncRegistrationCallbacks* callbacks);
   void getRegistrations(
       blink::WebSyncRegistration::Periodicity periodicity,
       blink::WebServiceWorkerRegistration* service_worker_registration,
       blink::WebSyncGetRegistrationsCallbacks* callbacks);
 
  private:
   // Callback handlers
   void RegisterCallback(
       scoped_ptr<blink::WebSyncRegistrationCallbacks> callbacks,
+      BackgroundSyncError error,
       const SyncRegistrationPtr& options);
   void UnregisterCallback(
       scoped_ptr<blink::WebSyncUnregistrationCallbacks> callbacks,
-      bool success);
+      BackgroundSyncError error);
+  void GetRegistrationCallback(
+      scoped_ptr<blink::WebSyncRegistrationCallbacks> callbacks,
+      BackgroundSyncError error,
+      const SyncRegistrationPtr& options);
   void GetRegistrationsCallback(
       scoped_ptr<blink::WebSyncGetRegistrationsCallbacks> callbacks,
+      BackgroundSyncError error,
       const mojo::Array<SyncRegistrationPtr>& registrations);
 
   // Helper method that returns an initialized BackgroundSyncServicePtr.
   BackgroundSyncServicePtr& GetBackgroundSyncServicePtr();
 
   ServiceRegistry* service_registry_;
   BackgroundSyncServicePtr background_sync_service_;
 
   DISALLOW_COPY_AND_ASSIGN(BackgroundSyncProvider);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_CHILD_BACKGROUND_SYNC_BACKGROUND_SYNC_PROVIDER_H_