Add gcm, nfc and bluetooth to GN build.

components/signin.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.
 
 {
   'targets': [
     {
+      # GN version: //components/signin/core/common
       'target_name': 'signin_core_common',
       'type': 'static_library',
       'include_dirs': [
         '..',
       ],
       'sources': [
         'signin/core/common/signin_pref_names.cc',
         'signin/core/common/signin_pref_names.h',
         'signin/core/common/signin_switches.cc',
         'signin/core/common/signin_switches.h',
         'signin/core/common/profile_management_switches.cc',
         'signin/core/common/profile_management_switches.h',
       ],
     },
     {
+      # GN version: //components/signin/core/browser
       'target_name': 'signin_core_browser',
       'type': 'static_library',
       'dependencies': [
         '../base/base.gyp:base',
         '../crypto/crypto.gyp:crypto',
         '../google_apis/google_apis.gyp:google_apis',
         '../net/net.gyp:net',
         '../sql/sql.gyp:sql',
         '../third_party/icu/icu.gyp:icui18n',
         '../third_party/icu/icu.gyp:icuuc',
         'keyed_service_core',
         'os_crypt',
         'signin_core_common',
         'webdata_common',
       ],
       'include_dirs': [
         '..',
       ],
       'sources': [
+        # Note: file list duplicated in GN build.
         'signin/core/browser/about_signin_internals.cc',
         'signin/core/browser/about_signin_internals.h',
         'signin/core/browser/account_reconcilor.cc',
         'signin/core/browser/account_reconcilor.h',
         'signin/core/browser/account_service_flag_fetcher.cc',
         'signin/core/browser/account_service_flag_fetcher.h',
         'signin/core/browser/mutable_profile_oauth2_token_service.cc',
         'signin/core/browser/mutable_profile_oauth2_token_service.h',
         'signin/core/browser/profile_oauth2_token_service.cc',
         'signin/core/browser/profile_oauth2_token_service.h',
@@ skipping 32 matching lines @@
         ['chromeos==1', {
           'sources!': [
             'signin/core/browser/signin_manager.cc',
           ],
         }],
       ],
       # TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
       'msvs_disabled_warnings': [4267, ],
     },
     {
+      # GN version: //components/signin/core/browser:test_support
       'target_name': 'signin_core_browser_test_support',
       'type': 'static_library',
       'dependencies': [
         'signin_core_browser',
         '../testing/gtest.gyp:gtest',
       ],
       'include_dirs': [
         '..',
       ],
       'sources': [
+        # Note: file list duplicated in GN build.
         'signin/core/browser/fake_auth_status_provider.cc',
         'signin/core/browser/fake_auth_status_provider.h',
         'signin/core/browser/test_signin_client.cc',
         'signin/core/browser/test_signin_client.h',
       ],
     },
   ],
   'conditions': [
     ['OS == "ios"', {
       'targets': [
         {
+          # GN version: //components/signin/core/browser:ios
           'target_name': 'signin_ios_browser',
           'type': 'static_library',
           'dependencies': [
             'signin_core_browser',
             '../ios/provider/ios_components.gyp:ios_components',
           ],
           'include_dirs': [
             '..',
           ],
           'sources': [
+            # Note: file list duplicated in GN build.
             'signin/ios/browser/profile_oauth2_token_service_ios.h',
             'signin/ios/browser/profile_oauth2_token_service_ios.mm',
           ],
         },
       ],
     }],
   ],
 }