Introduce //components/user_prefs, use to eliminate c/b/prefs dependency in Autofill.

chrome/chrome_browser.gypi

 # Copyright 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.
 
 {
   'targets': [
     {
       'target_name': 'browser',
       'type': 'static_library',
       'variables': { 'enable_wexit_time_destructors': 1, },
       'dependencies': [
         # NOTE: New dependencies should generally be added in the OS!="ios"
         # dependencies block below, rather than here.
         'browser/search_engines/prepopulated_engines.gyp:prepopulated_engines',
         'browser_ui',
         'cert_logger_proto',
         'chrome_resources.gyp:chrome_extra_resources',
         'chrome_resources.gyp:chrome_resources',
         'chrome_resources.gyp:chrome_strings',
         'chrome_resources.gyp:platform_locale_settings',
         'chrome_resources.gyp:theme_resources',
         'common',
         'common_net',
         'feedback_proto',
         'in_memory_url_index_cache_proto',
         'safe_browsing_proto',
         'safe_browsing_report_proto',
         'variations_seed_proto',
         '../build/temp_gyp/googleurl.gyp:googleurl',
+        '../components/components.gyp:user_prefs',
         '../components/components.gyp:visitedlink_browser',
         '../components/components.gyp:visitedlink_common',
         '../content/content.gyp:content_browser',
         '../content/content.gyp:content_common',
         '../crypto/crypto.gyp:crypto',
         '../google_apis/google_apis.gyp:google_apis',
         '../media/media.gyp:media',
         '../skia/skia.gyp:skia',
         '../sql/sql.gyp:sql',
         '../sync/sync.gyp:sync',
@@ skipping 1442 matching lines @@
         'browser/prefs/browser_prefs.cc',
         'browser/prefs/browser_prefs.h',
         'browser/prefs/chrome_pref_service_factory.cc',
         'browser/prefs/chrome_pref_service_factory.h',
         'browser/prefs/command_line_pref_store.cc',
         'browser/prefs/command_line_pref_store.h',
         'browser/prefs/incognito_mode_prefs.cc',
         'browser/prefs/incognito_mode_prefs.h',
         'browser/prefs/pref_model_associator.cc',
         'browser/prefs/pref_model_associator.h',
-        'browser/prefs/pref_registry_syncable.cc',
-        'browser/prefs/pref_registry_syncable.h',
         'browser/prefs/pref_service_syncable.cc',
         'browser/prefs/pref_service_syncable.h',
         'browser/prefs/pref_service_syncable_builder.cc',
         'browser/prefs/pref_service_syncable_builder.h',
         'browser/prefs/pref_service_syncable_observer.h',
         'browser/prefs/proxy_config_dictionary.cc',
         'browser/prefs/proxy_config_dictionary.h',
         'browser/prefs/proxy_prefs.cc',
         'browser/prefs/proxy_prefs.h',
         'browser/prefs/scoped_user_pref_update.cc',
@@ skipping 1624 matching lines @@
           'variables': {
             'jni_gen_dir': 'chrome',
           },
           'includes': [ '../build/jni_generator.gypi' ],
         },
       ],
      },
     ],
   ],
 }