Revert of Disable flaky CommandLineExtensionsDontLoad test

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 266 matching lines @@
  protected:
   void SetUpCommandLine(base::CommandLine* command_line) override {
     ExtensionsLoadTest::SetUpCommandLine(command_line);
     // TODO(emaxx): Remove this test fixture class once the
     // EnableLoginScreenApps command line flag becomes on by default.
     // crbug.com/576464
     command_line->AppendSwitch(switches::kEnableLoginScreenApps);
   }
 };
 
-// Flaky test crbug.com/716727
 IN_PROC_BROWSER_TEST_F(ExtensionsLoadTestWithLoginScreenApps,
-                       DISABLED_CommandLineExtensionsDontLoad) {
+                       CommandLineExtensionsDontLoad) {
   // The --load-extension command line flag should not be applied to the sign-in
   // profile.
   EXPECT_EQ(0, GetNonComponentEnabledExtensionCount(
                    chromeos::ProfileHelper::GetSigninProfile()));
 }
 
 #endif  // defined(OS_CHROMEOS)
 
 // ExtensionsLoadMultipleTest
 // Ensures that we can startup the browser with multiple extensions
@@ skipping 124 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);
 }