Update GN build files for new prefs location.

components/policy/core/common/BUILD.gn

 # 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.
 
 import("//build/config/features.gni")
 
 source_set("common") {
   visibility = [
     "//components/policy/*",
     "//components/syncable_prefs/*",
@@ skipping 118 matching lines @@
       "schema_registry_tracking_policy_provider.h",
     ]
 
     configs += [ "//build/config:precompiled_headers" ]
 
     public_deps = [
       "//components/policy/proto",
     ]
     deps = [
       "//base:i18n",
-      "//base:prefs",
       "//base/third_party/dynamic_annotations",
       "//components/data_use_measurement/core",
       "//components/json_schema",
       "//components/policy",
+      "//components/prefs",
       "//google_apis",
       "//net",
       "//third_party/re2",
       "//url",
     ]
 
     if (is_win) {
       libs = [ "netapi32.lib" ]
     }
     if (is_android) {
@@ skipping 122 matching lines @@
         "cloud/component_cloud_policy_updater_unittest.cc",
         "cloud/external_policy_data_fetcher_unittest.cc",
         "cloud/external_policy_data_updater_unittest.cc",
         "cloud/resource_cache_unittest.cc",
         "config_dir_policy_loader_unittest.cc",
       ]
     }
 
     deps = [
       "//base",
-      "//base:prefs_test_support",
       "//base/test:test_support",
       "//components/policy",
       "//components/policy:policy_component_test_support",
+    "//components/prefs:test_support",
+      "//components/prefs:test_support",
       "//google_apis",
       "//net:test_support",
       "//testing/gmock",
       "//testing/gtest",
     ]
   }
 }