Define PushMessagingApplicationId and replace ad-hoc code.

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': [
     '../base/base.gyp:base_static',
     '../crypto/crypto.gyp:crypto',
     '../google_apis/google_apis.gyp:google_apis',
     '../net/net.gyp:net',
@@ skipping 151 matching lines @@
       'public/browser/overscroll_configuration.h',
       'public/browser/page_navigator.cc',
       'public/browser/page_navigator.h',
       'public/browser/pepper_flash_settings_helper.h',
       'public/browser/plugin_data_remover.h',
       'public/browser/plugin_service.h',
       'public/browser/plugin_service_filter.h',
       'public/browser/power_save_blocker.h',
       'public/browser/profiler_controller.h',
       'public/browser/profiler_subscriber.h',
+      'public/browser/push_messaging_application_id.cc',
+      'public/browser/push_messaging_application_id.h',
+      'public/browser/push_messaging_service.h',
       'public/browser/quota_permission_context.h',
       'public/browser/render_frame_host.h',
       'public/browser/render_process_host.h',
       'public/browser/render_process_host_factory.h',
       'public/browser/render_process_host_observer.h',
       'public/browser/render_view_host.h',
       'public/browser/render_widget_host.h',
       'public/browser/render_widget_host_view.h',
       'public/browser/render_widget_host_view_frame_subscriber.h',
       'public/browser/render_widget_host_view_mac_delegate.h',
@@ skipping 1658 matching lines @@
       'sources': [
         'browser/media/cdm/browser_cdm_manager.cc',
         'browser/media/cdm/browser_cdm_manager.h',
         # This works on Android because enable_browser_cdms==1 on Android.
         'browser/media/media_web_contents_observer.cc',
         'browser/media/media_web_contents_observer.h',
       ],
     }],
   ],
 }