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

chrome/browser/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/crypto.gni")
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
 import("//build/split_static_library.gni")
 import("//chrome/common/features.gni")
@@ skipping 908 matching lines @@
     "profiles/bookmark_model_loaded_observer.cc",
     "profiles/bookmark_model_loaded_observer.h",
     "profiles/chrome_browser_main_extra_parts_profiles.cc",
     "profiles/chrome_browser_main_extra_parts_profiles.h",
     "profiles/chrome_version_service.cc",
     "profiles/chrome_version_service.h",
     "profiles/gaia_info_update_service.cc",
     "profiles/gaia_info_update_service.h",
     "profiles/gaia_info_update_service_factory.cc",
     "profiles/gaia_info_update_service_factory.h",
+    "profiles/guest_mode_policy_handler.cc",
+    "profiles/guest_mode_policy_handler.h",
     "profiles/incognito_helpers.cc",
     "profiles/incognito_helpers.h",
     "profiles/incognito_mode_policy_handler.cc",
     "profiles/incognito_mode_policy_handler.h",
     "profiles/off_the_record_profile_impl.cc",
     "profiles/off_the_record_profile_impl.h",
     "profiles/off_the_record_profile_io_data.cc",
     "profiles/off_the_record_profile_io_data.h",
     "profiles/profile.cc",
     "profiles/profile.h",
@@ skipping 3485 matching lines @@
   # linking all of the test support.
   static_library("pepper_cdm_test_constants") {
     testonly = true
     visibility = [ "//chrome/*" ]
     sources = [
       "media/pepper_cdm_test_constants.cc",
       "media/pepper_cdm_test_constants.h",
     ]
   }
 }