Cleanup inconsistencies between GN and GYP in //remoting

remoting/remoting_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': {
     'daemon_controller_guid': '655bd819-c08c-4b04-80c2-f160739ff6ef',
     'rdp_desktop_session_guid': '6a7699f0-ee43-43e7-aa30-a6738f9bd470',
     'remoting_base_sources': [
       'base/auto_thread.cc',
@@ skipping 181 matching lines @@
       'protocol/third_party_client_authenticator.h',
       'protocol/third_party_host_authenticator.cc',
       'protocol/third_party_host_authenticator.h',
       'protocol/token_validator.h',
       'protocol/transport.cc',
       'protocol/transport.h',
       'protocol/usb_key_codes.h',
       'protocol/v2_authenticator.cc',
       'protocol/v2_authenticator.h',
       'protocol/video_stub.h',
+    ],
+
+    'remoting_signaling_sources': [
       'signaling/iq_sender.cc',
       'signaling/iq_sender.h',
       'signaling/jid_util.cc',
       'signaling/jid_util.h',
       'signaling/jingle_info_request.cc',
       'signaling/jingle_info_request.h',
       'signaling/log_to_server.cc',
       'signaling/log_to_server.h',
       'signaling/push_notification_subscriber.cc',
       'signaling/push_notification_subscriber.h',
@@ skipping 71 matching lines @@
       'client/plugin/pepper_util.cc',
       'client/plugin/pepper_util.h',
       'client/plugin/pepper_video_renderer.h',
       'client/plugin/pepper_video_renderer_2d.cc',
       'client/plugin/pepper_video_renderer_2d.h',
       'client/plugin/pepper_video_renderer_3d.cc',
       'client/plugin/pepper_video_renderer_3d.h',
     ],
   }
 }