Add skeleton implementation of ExtensionPushMessagingEventRouter.

chrome/chrome_browser_extensions.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.
 
 {
   'targets': [
     {
       'target_name': 'browser_extensions',
       'type': 'static_library',
       'variables': { 'enable_wexit_time_destructors': 1, },
@@ skipping 164 matching lines @@
         'browser/extensions/api/permissions/permissions_api.cc',
         'browser/extensions/api/permissions/permissions_api.h',
         'browser/extensions/api/permissions/permissions_api_helpers.cc',
         'browser/extensions/api/permissions/permissions_api_helpers.h',
         'browser/extensions/api/proxy/proxy_api.cc',
         'browser/extensions/api/proxy/proxy_api.h',
         'browser/extensions/api/proxy/proxy_api_constants.cc',
         'browser/extensions/api/proxy/proxy_api_constants.h',
         'browser/extensions/api/proxy/proxy_api_helpers.cc',
         'browser/extensions/api/proxy/proxy_api_helpers.h',
+        'browser/extensions/api/push_messaging/invalidation_handler_observer.h',
+        'browser/extensions/api/push_messaging/push_messaging_api.cc',
+        'browser/extensions/api/push_messaging/push_messaging_api.h',
         'browser/extensions/api/record/record_api.cc',
         'browser/extensions/api/record/record_api.h',
         'browser/extensions/api/runtime/runtime_api.cc',
         'browser/extensions/api/runtime/runtime_api.h',
         'browser/extensions/api/serial/serial_api.cc',
         'browser/extensions/api/serial/serial_api.h',
         'browser/extensions/api/serial/serial_connection.cc',
         'browser/extensions/api/serial/serial_connection.h',
         'browser/extensions/api/serial/serial_connection_posix.cc',
         'browser/extensions/api/serial/serial_connection_win.cc',
@@ skipping 562 matching lines @@
           'sources': [
             'browser/extensions/app_host.rc',
             'browser/extensions/app_host_stub_main.cc',
           ],
         },
       ],
     }, ],  # 'OS=="win"'
   ],  # 'conditions'
 }