Cleanup inconsistencies between GN and GYP in //remoting

remoting/remoting_nacl.gyp

 # 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.
 
 {
   'includes': [
     '../build/common_untrusted.gypi',
     'remoting_srcs.gypi',
   ],
 
@@ skipping 101 matching lines @@
         'remoting_proto_nacl',
         'remoting_webrtc_nacl',
       ],
       'sources': [
         '../ui/events/keycodes/dom/keycode_converter.cc',
         '<@(remoting_base_sources)',
         '<@(remoting_codec_sources)',
         '<@(remoting_client_plugin_sources)',
         '<@(remoting_client_sources)',
         '<@(remoting_protocol_sources)',
+        '<@(remoting_signaling_sources)',
       ],
       'sources!': [
         'base/url_request_context_getter.cc',
         'protocol/chromium_socket_factory.cc',
       ],
 
       # Include normalizing_input_filter_mac.cc excluded by the filename
       # exclusion rules. Must be in target_conditions to make sure it's
       # evaluated after the filename rules.
       'target_conditions': [
@@ skipping 99 matching lines @@
         '-lppapi_cpp',
         '-lpthread',
         '-lnacl_io',
       ],
       'sources': [
         'client/plugin/pepper_module.cc',
       ],
     },  # end of target 'remoting_client_plugin_nacl'
   ]
 }