Removing extensions::FeatureSwitch which is no longer used

chrome/browser/extensions/extension_browsertest.h

 // 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.
 
 #ifndef CHROME_BROWSER_EXTENSIONS_EXTENSION_BROWSERTEST_H_
 #define CHROME_BROWSER_EXTENSIONS_EXTENSION_BROWSERTEST_H_
 
 #include <string>
 
 #include "base/command_line.h"
@@ skipping 355 matching lines @@
       extensions::Manifest::Location install_source,
       Browser* browser,
       extensions::Extension::InitFromValueFlags creation_flags,
       bool wait_for_idle,
       bool is_ephemeral);
 
   // Make the current channel "dev" for the duration of the test.
   extensions::ScopedCurrentChannel current_channel_;
 
   // Disable external install UI.
-  extensions::FeatureSwitch::ScopedOverride
       override_prompt_for_external_extensions_;
 
 #if defined(OS_WIN)
   // Use mock shortcut directories to ensure app shortcuts are cleaned up.
   base::ScopedPathOverride user_desktop_override_;
   base::ScopedPathOverride common_desktop_override_;
   base::ScopedPathOverride user_quick_launch_override_;
   base::ScopedPathOverride start_menu_override_;
   base::ScopedPathOverride common_start_menu_override_;
 #endif
 
   // The default profile to be used.
   Profile* profile_;
 
   // Cache cache implementation.
   scoped_ptr<extensions::ExtensionCacheFake> test_extension_cache_;
 };
 
 #endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_BROWSERTEST_H_