components: Extract pref_registry component out of user_prefs.

extensions/extensions.gyp

 # Copyright 2013 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.
 
 {
   'variables': {
     'chromium_code': 1,
   },
   'targets': [
     {
@@ skipping 204 matching lines @@
             'common/extension_api.cc',
           ],
         }],
       ],
     },
     {
       'target_name': 'extensions_browser',
       'type': 'static_library',
       'dependencies': [
         '../components/components.gyp:keyed_service_content',
+        '../components/components.gyp:pref_registry',
         '../components/components.gyp:usb_service',
         '../content/content.gyp:content_browser',
         '../skia/skia.gyp:skia',
         '../third_party/leveldatabase/leveldatabase.gyp:leveldatabase',
         'common/api/api.gyp:extensions_api',
         'extensions_common',
         'extensions_strings.gyp:extensions_strings',
       ],
       'include_dirs': [
         '..',
@@ skipping 377 matching lines @@
         'test/test_extensions_client.cc',
         'test/test_extensions_client.h',
         'test/test_permission_message_provider.cc',
         'test/test_permission_message_provider.h',
         'test/test_permissions_provider.cc',
         'test/test_permissions_provider.h',
       ],
     },
   ]
 }