MD User Manager: Supervised user logic should be inside ENABLE_SUPERVISED_USERS flag

chrome/chrome_browser_ui.gypi

 # Copyright 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.
 
 {
   'variables': {
     # There are two sections of sources:
     # * "Platform"-based sources (OS, toolkit, etc.)
     # * Feature/directory-based sources (e.g., history, printing)
 
@@ skipping 3306 matching lines @@
           'sources': [ '<@(chrome_browser_ui_media_router_sources)' ],
         }],
         ['enable_supervised_users==0', {
           'sources!': [
             'browser/ui/webui/options/supervised_user_create_confirm_handler.cc',
             'browser/ui/webui/options/supervised_user_create_confirm_handler.h',
             'browser/ui/webui/options/supervised_user_import_handler.cc',
             'browser/ui/webui/options/supervised_user_import_handler.h',
             'browser/ui/webui/options/supervised_user_learn_more_handler.cc',
             'browser/ui/webui/options/supervised_user_learn_more_handler.h',
+            'browser/ui/webui/signin/signin_supervised_user_import_handler.cc',
+            'browser/ui/webui/signin/signin_supervised_user_import_handler.h',
           ],
         }],
         ['enable_webrtc==1', {
           'sources': [ '<@(chrome_browser_ui_webrtc_sources)' ],
         }],
         ['enable_service_discovery==1', {
           'sources': [ '<@(chrome_browser_ui_service_discovery_sources)' ],
         }],
         ['enable_extensions==1', {
           'dependencies': [
@@ skipping 16 matching lines @@
           ],
           'sources': [
             '<@(chrome_browser_ui_non_mobile_sources)',
             '<@(chrome_browser_ui_omnibox_non_mobile_sources)',
           ],
         }],
       ],
     },
   ],
 }