components: Extract pref_registry component out of user_prefs.

components/policy/policy_browser.gypi

 # Copyright 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.
 
 {
   'dependencies': [
     '../base/base.gyp:base',
     '../base/base.gyp:base_prefs',
     '../base/third_party/dynamic_annotations/dynamic_annotations.gyp:dynamic_annotations',
     '../net/net.gyp:net',
     '../ui/base/ui_base.gyp:ui_base',
     '../url/url.gyp:url_lib',
     'components_strings.gyp:components_strings',
+    'pref_registry',
     'url_matcher',
-    'user_prefs',
   ],
   'defines': [
     'POLICY_COMPONENT_IMPLEMENTATION',
   ],
   'include_dirs': [
     '..',
   ],
   'sources': [
     # Note that these sources are always included, even for builds that
     # disable policy. Most source files should go in the conditional
@@ skipping 26 matching lines @@
         'core/browser/configuration_policy_pref_store.cc',
         'core/browser/configuration_policy_pref_store.h',
         'core/browser/policy_error_map.cc',
         'core/browser/policy_error_map.h',
         'core/browser/url_blacklist_policy_handler.cc',
         'core/browser/url_blacklist_policy_handler.h',
       ],
     }],
   ],
 }