Add some empty classes for the embedded SharedWorker.

content/content_browser.gypi

 # Copyright (c) 2012 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.
 
 {
   'dependencies': [
     '../third_party/re2/re2.gyp:re2',
     '../base/base.gyp:base_static',
     '../crypto/crypto.gyp:crypto',
     '../google_apis/google_apis.gyp:google_apis',
@@ skipping 1110 matching lines @@
     'browser/service_worker/service_worker_register_job.cc',
     'browser/service_worker/service_worker_register_job.h',
     'browser/service_worker/service_worker_registration.cc',
     'browser/service_worker/service_worker_registration.h',
     'browser/service_worker/service_worker_registration_status.cc',
     'browser/service_worker/service_worker_registration_status.h',
     'browser/service_worker/service_worker_storage.cc',
     'browser/service_worker/service_worker_storage.h',
     'browser/service_worker/service_worker_version.cc',
     'browser/service_worker/service_worker_version.h',
+    'browser/shared_worker/shared_worker_service_impl.cc',
+    'browser/shared_worker/shared_worker_service_impl.h',
     'browser/signed_certificate_timestamp_store_impl.cc',
     'browser/signed_certificate_timestamp_store_impl.h',
     'browser/site_instance_impl.cc',
     'browser/site_instance_impl.h',
     'browser/speech/audio_buffer.cc',
     'browser/speech/audio_buffer.h',
     'browser/speech/audio_encoder.cc',
     'browser/speech/audio_encoder.h',
     'browser/speech/chunked_byte_buffer.cc',
     'browser/speech/chunked_byte_buffer.h',
@@ skipping 507 matching lines @@
         '../build/linux/system.gyp:dbus',
         '../dbus/dbus.gyp:dbus',
       ],
     }, {  # OS != "linux" or use_dbus==0
       'sources!': [
         'browser/geolocation/wifi_data_provider_linux.cc',
       ],
     }],
   ],
 }