[OnionSoup] Move background_sync.mojom from //content to //third_party/WebKit

content/content_common_mojo_bindings.gyp

 # Copyright 2014 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.
 
 {
   'targets': [
     {
       # GN version: //content/common:mojo_bindings
       'target_name': 'content_common_mojo_bindings_mojom',
       'type': 'none',
       'variables': {
         'mojom_files': [
           # NOTE: Sources duplicated in //content/common/BUILD.gn:mojo_bindings.
           'common/application_setup.mojom',
-          'common/background_sync_service.mojom',
           'common/image_downloader/image_downloader.mojom',
           'common/leveldb_wrapper.mojom',
           'common/presentation/presentation_service.mojom',
           'common/process_control.mojom',
           'common/render_frame_setup.mojom',
           'common/service_worker/embedded_worker_setup.mojom',
           'common/storage_partition_service.mojom',
-
-          # NOTE: Sources duplicated in
-          # //content/public/common/BUILD.gn:mojo_bindings.
-          'public/common/background_sync.mojom',
-          'public/common/service_worker_event_status.mojom',
         ],
         'mojom_typemaps': [
           '../url/mojo/gurl.typemap',
           '../url/mojo/origin.typemap',
         ],
       },
       'dependencies': [
         '../components/leveldb/leveldb.gyp:leveldb_bindings_mojom',
         '../mojo/mojo_public.gyp:mojo_cpp_bindings',
         '../services/shell/shell.gyp:shell_public',
@@ skipping 12 matching lines @@
       'dependencies': [
         '../url/url.gyp:url_mojom',
         'content_common_mojo_bindings_mojom',
       ],
       'export_dependent_settings': [
         '../url/url.gyp:url_mojom',
       ],
     },
   ]
 }