Added class to subscribe to GCD notifications over XMPP.

remoting/remoting_host_srcs.gypi

 # 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.
 
 {
   'variables': {
     'remoting_host_sources': [
       'host/audio_capturer.cc',
       'host/audio_capturer.h',
       'host/audio_capturer_linux.cc',
@@ skipping 76 matching lines @@
       'host/desktop_shape_tracker_linux.cc',
       'host/desktop_shape_tracker_mac.cc',
       'host/desktop_shape_tracker_win.cc',
       'host/disconnect_window_chromeos.cc',
       'host/disconnect_window_linux.cc',
       'host/disconnect_window_mac.h',
       'host/disconnect_window_mac.mm',
       'host/disconnect_window_win.cc',
       'host/dns_blackhole_checker.cc',
       'host/dns_blackhole_checker.h',
+      'host/gcd_notification_subscriber.cc',
+      'host/gcd_notification_subscriber.h',
       'host/gnubby_auth_handler.h',
       'host/gnubby_auth_handler_posix.cc',
       'host/gnubby_auth_handler_posix.h',
       'host/gnubby_auth_handler_win.cc',
       'host/gnubby_socket.cc',
       'host/gnubby_socket.h',
       'host/heartbeat_sender.cc',
       'host/heartbeat_sender.h',
       'host/host_change_notification_listener.cc',
       'host/host_change_notification_listener.h',
@@ skipping 203 matching lines @@
       'host/it2me/it2me_confirmation_dialog_chromeos.cc',
       'host/it2me/it2me_confirmation_dialog_proxy.cc',
       'host/it2me/it2me_confirmation_dialog_proxy.h',
       'host/it2me/it2me_host.cc',
       'host/it2me/it2me_host.h',
       'host/it2me/it2me_native_messaging_host.cc',
       'host/it2me/it2me_native_messaging_host.h',
     ],
   }
 }