Converted IncognitoForced boolean policy into IncognitoModeAvailability enum policy.

chrome/chrome_browser.gypi

 # Copyright (c) 2011 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': [
     {
       'target_name': 'browser',
       'type': 'static_library',
       'dependencies': [
@@ skipping 1676 matching lines @@
         '<(protoc_out_dir)/chrome/browser/policy/proto/device_management_local.pb.cc',
         '<(protoc_out_dir)/chrome/browser/policy/proto/device_management_local.pb.h',
         'browser/preferences_mac.cc',
         'browser/preferences_mac.h',
         'browser/prefs/browser_prefs.cc',
         'browser/prefs/browser_prefs.h',
         'browser/prefs/command_line_pref_store.cc',
         'browser/prefs/command_line_pref_store.h',
         'browser/prefs/default_pref_store.cc',
         'browser/prefs/default_pref_store.h',
+        'browser/prefs/incognito_mode_prefs.cc',
+        'browser/prefs/incognito_mode_prefs.h',
         'browser/prefs/incognito_user_pref_store.cc',
         'browser/prefs/incognito_user_pref_store.h',
         'browser/prefs/pref_change_registrar.cc',
         'browser/prefs/pref_change_registrar.h',
         'browser/prefs/pref_member.cc',
         'browser/prefs/pref_member.h',
         'browser/prefs/pref_model_associator.cc',
         'browser/prefs/pref_model_associator.h',
         'browser/prefs/pref_notifier.h',
         'browser/prefs/pref_notifier_impl.cc',
@@ skipping 3174 matching lines @@
       ],
       'export_dependent_settings': [
         'in_memory_url_index_cache_proto',
       ],
       # This target exports a hard dependency because it includes generated
       # header files.
       'hard_dependency': 1,
     },
   ],
 }