Enable settings hardening on OSX when no Finch config is present

chrome/browser/extensions/extension_startup_browsertest.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 <stddef.h>
 #include <stdint.h>
 
 #include <vector>
 
 #include "base/base_switches.h"
@@ skipping 49 matching lines @@
   void SetUpCommandLine(base::CommandLine* command_line) override {
     if (load_extensions_.empty()) {
       // If no |load_extensions_| were specified, allow unauthenticated
       // extension settings to be loaded from Preferences as if they had been
       // authenticated correctly before they were handed to the ExtensionSystem.
       command_line->AppendSwitchASCII(
           switches::kForceFieldTrials,
           base::StringPrintf(
               "%s/%s/", chrome_prefs::internals::kSettingsEnforcementTrialName,
               chrome_prefs::internals::kSettingsEnforcementGroupNoEnforcement));
-#if defined(OFFICIAL_BUILD) && defined(OS_WIN)
-      // In Windows official builds, it is not possible to disable settings
-      // authentication.
+#if defined(OFFICIAL_BUILD) && (defined(OS_WIN) || defined(OS_MACOSX))
+      // In Windows and MacOS official builds, it is not possible to disable
+      // settings enforcement.
       unauthenticated_load_allowed_ = false;
 #endif
     } else {
       base::FilePath::StringType paths = base::JoinString(
           load_extensions_, base::FilePath::StringType(1, ','));
       command_line->AppendSwitchNative(switches::kLoadExtension, paths);
       command_line->AppendSwitch(switches::kDisableExtensionsFileAccessCheck);
     }
   }
 
@@ skipping 313 matching lines @@
     } else if (extension->name() == "App Test") {
       is_app_test_extension_enabled = true;
     } else {
       EXPECT_TRUE(
           extensions::Manifest::IsComponentLocation(extension->location()));
     }
   }
   EXPECT_TRUE(is_app_dot_com_extension_enabled);
   EXPECT_TRUE(is_app_test_extension_enabled);
 }