Disable guest mode by default if force sign in is enabled.

chrome/test/BUILD.gn

 # 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.
 
 import("//build/config/chrome_build.gni")
 import("//build/config/compiler/compiler.gni")
 import("//build/config/crypto.gni")
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
 import("//chrome/common/features.gni")
@@ skipping 3241 matching lines @@
     "../browser/prefs/proxy_policy_unittest.cc",
     "../browser/prefs/session_startup_pref_unittest.cc",
     "../browser/prerender/prerender_history_unittest.cc",
     "../browser/prerender/prerender_resource_throttle_unittest.cc",
     "../browser/prerender/prerender_unittest.cc",
     "../browser/prerender/prerender_util_unittest.cc",
     "../browser/previews/previews_infobar_delegate_unittest.cc",
     "../browser/previews/previews_infobar_tab_helper_unittest.cc",
     "../browser/process_singleton_win_unittest.cc",
     "../browser/profiles/gaia_info_update_service_unittest.cc",
+    "../browser/profiles/guest_mode_policy_handler_unittest.cc",
     "../browser/profiles/incognito_mode_policy_handler_unittest.cc",
     "../browser/profiles/profile_attributes_storage_unittest.cc",
     "../browser/profiles/profile_avatar_icon_util_unittest.cc",
     "../browser/profiles/profile_downloader_unittest.cc",
     "../browser/profiles/profile_info_cache_unittest.cc",
     "../browser/profiles/profile_info_cache_unittest.h",
     "../browser/profiles/profile_manager_unittest.cc",
     "../browser/profiles/profile_shortcut_manager_unittest_win.cc",
     "../browser/push_messaging/push_messaging_app_identifier_unittest.cc",
     "../browser/push_messaging/push_messaging_notification_manager_unittest.cc",
@@ skipping 1846 matching lines @@
 }
 
 if (is_win) {
   loadable_module("conflicts_dll") {
     testonly = true
     sources = [
       "conflicts/conflicts_dll.cc",
     ]
   }
 }