Enable settings hardening on OSX when no Finch config is present

chrome/browser/prefs/chrome_pref_service_factory.cc

 // Copyright (c) 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.
 
 #include <chrome/browser/prefs/chrome_command_line_pref_store.h>
 #include "chrome/browser/prefs/chrome_pref_service_factory.h"
 
 #include <stddef.h>
 
 #include <string>
@@ skipping 212 matching lines @@
       GROUP_ENFORCE_ALWAYS },
     { chrome_prefs::internals::
           kSettingsEnforcementGroupEnforceAlwaysWithDSE,
       GROUP_ENFORCE_ALWAYS_WITH_DSE },
     { chrome_prefs::internals::
           kSettingsEnforcementGroupEnforceAlwaysWithExtensionsAndDSE,
       GROUP_ENFORCE_ALWAYS_WITH_EXTENSIONS_AND_DSE },
   };
 
   // Use the strongest enforcement setting in the absence of a field trial
-  // config on Windows. Remember to update the OFFICIAL_BUILD section of
-  // extension_startup_browsertest.cc and pref_hash_browsertest.cc when updating
-  // the default value below.
+  // config on Windows and MacOS. Remember to update the OFFICIAL_BUILD section
+  // of extension_startup_browsertest.cc and pref_hash_browsertest.cc when
+  // updating the default value below.
   // TODO(gab): Enforce this on all platforms.
   SettingsEnforcementGroup enforcement_group =
-#if defined(OS_WIN)
+#if defined(OS_WIN) || defined(OS_MACOSX)
       GROUP_ENFORCE_DEFAULT;
 #else
       GROUP_NO_ENFORCEMENT;
 #endif
   bool group_determined_from_trial = false;
   base::FieldTrial* trial =
       base::FieldTrialList::Find(
           chrome_prefs::internals::kSettingsEnforcementTrialName);
   if (trial) {
     const std::string& group_name = trial->group_name();
@@ skipping 234 matching lines @@
 
 void ClearResetTime(Profile* profile) {
   ProfilePrefStoreManager::ClearResetTime(profile->GetPrefs());
 }
 
 void RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* registry) {
   ProfilePrefStoreManager::RegisterProfilePrefs(registry);
 }
 
 }  // namespace chrome_prefs