components: Extract pref_registry component out of user_prefs.

components/bookmarks.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.
 
 {
   'targets': [
     {
       'target_name': 'bookmarks_core_browser',
       'type': 'static_library',
       'include_dirs': [
         '..',
       ],
       'dependencies': [
         '../base/base.gyp:base',
         '../net/net.gyp:net',
         '../third_party/icu/icu.gyp:icuuc',
         '../ui/base/ui_base.gyp:ui_base',
         '../ui/gfx/gfx.gyp:gfx',
         '../url/url.gyp:url_lib',
         'bookmarks_core_common',
         'components_strings.gyp:components_strings',
         'favicon_base',
         'query_parser',
         'startup_metric_utils',
-        'user_prefs',
+        'pref_registry',
       ],
       'sources': [
         'bookmarks/core/browser/base_bookmark_model_observer.cc',
         'bookmarks/core/browser/base_bookmark_model_observer.h',
         'bookmarks/core/browser/bookmark_client.cc',
         'bookmarks/core/browser/bookmark_client.h',
         'bookmarks/core/browser/bookmark_codec.cc',
         'bookmarks/core/browser/bookmark_codec.h',
         'bookmarks/core/browser/bookmark_expanded_state_tracker.cc',
         'bookmarks/core/browser/bookmark_expanded_state_tracker.h',
@@ skipping 51 matching lines @@
       ],
       'sources': [
         'bookmarks/core/test/bookmark_test_helpers.cc',
         'bookmarks/core/test/bookmark_test_helpers.h',
         'bookmarks/core/test/test_bookmark_client.cc',
         'bookmarks/core/test/test_bookmark_client.h',
       ],
     },
   ],
 }