Componentize proxy code from chrome/browser/net

chrome/browser/extensions/settings_api_helpers.cc

 // Copyright (c) 2014 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/extensions/settings_api_helpers.h"
 
 #include "chrome/browser/extensions/api/preference/preference_api.h"
 #include "chrome/common/pref_names.h"
+#include "components/proxy_config/proxy_config_pref_names.h"
 #include "components/search_engines/search_engines_pref_names.h"
 #include "extensions/browser/extension_pref_value_map.h"
 #include "extensions/browser/extension_pref_value_map_factory.h"
 #include "extensions/browser/extension_registry.h"
 #include "extensions/common/extension_set.h"
 
 namespace extensions {
 
 namespace {
 
@@ skipping 61 matching lines @@
   return FindOverridingExtension(browser_context, BUBBLE_TYPE_SEARCH_ENGINE);
 }
 
 const Extension* GetExtensionOverridingProxy(
     content::BrowserContext* browser_context) {
   ExtensionPrefValueMap* extension_prefs_value_map =
       ExtensionPrefValueMapFactory::GetForBrowserContext(browser_context);
   if (!extension_prefs_value_map)
     return NULL;  // Can be null during testing.
   std::string extension_id =
-      extension_prefs_value_map->GetExtensionControllingPref(prefs::kProxy);
+      extension_prefs_value_map->GetExtensionControllingPref(
+          proxy_config::prefs::kProxy);
   if (extension_id.empty())
     return NULL;
   return ExtensionRegistry::Get(browser_context)->GetExtensionById(
       extension_id, ExtensionRegistry::ENABLED);
 }
 
 }  // namespace extensions