Add Mojo types and service definitions for Background Sync API

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.background_sync;
+
+import "background_sync.mojom";
+
+interface BackgroundSyncService {
+  Register(SyncRegistration options, string origin,
+           int64 serviceWorkerRegistrationId) => (SyncRegistration options);

[jkarlin, 2015/04/27 18:25:11]

service_worker_registration_id here and below

[iclelland, 2015/04/28 12:41:30]

Done.

+  GetRegistration(SyncPeriodicity periodicity, string tag, string origin,
+                  int64 serviceWorkerRegistrationId)
+      => (SyncRegistration? registration);
+  GetRegistrations(SyncPeriodicity periodicity, string origin,
+                   int64 serviceWorkerRegistrationId)
+      => (array<SyncRegistration> registrations);
+  Unregister(SyncPeriodicity periodicity, int32 id, string tag, string origin,

[jkarlin, 2015/04/27 18:25:11]

int64 id

[iclelland, 2015/04/28 12:41:30]

Done.

+             int64 serviceWorkerRegistrationId) => (bool success);
+};
+
+interface BackgoundSyncServiceClient {
+  Sync(SyncRegistration event);
+};
+