Update GN build files for new prefs location.

components/signin/core/browser/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.
 
 if (is_android) {
   import("//build/config/android/rules.gni")
 }
 
 source_set("browser") {
   sources = [
@@ skipping 57 matching lines @@
     "webdata/token_service_table.h",
     "webdata/token_web_data.cc",
     "webdata/token_web_data.h",
   ]
 
   configs += [ "//build/config/compiler:no_size_t_to_int_warning" ]
 
   deps = [
     "//base",
     "//base:i18n",
-    "//base:prefs",
     "//components/content_settings/core/browser",
     "//components/content_settings/core/common",
     "//components/google/core/browser",
     "//components/invalidation/public",
     "//components/keyed_service/core",
     "//components/metrics",
     "//components/os_crypt",
     "//components/pref_registry",
+    "//components/prefs",
     "//components/signin/core/account_id",
     "//components/signin/core/common",
     "//components/webdata/common",
     "//crypto",
     "//google_apis",
     "//net",
     "//sql",
     "//third_party/icu",
   ]
 
@@ skipping 25 matching lines @@
     "fake_profile_oauth2_token_service.h",
     "fake_signin_manager.cc",
     "fake_signin_manager.h",
     "test_signin_client.cc",
     "test_signin_client.h",
   ]
 
   public_deps = [
     ":browser",
     "//base",
-    "//base:prefs_test_support",
+    "//components/prefs:test_support",
     "//components/webdata/common",
     "//google_apis:test_support",
     "//net:test_support",
     "//testing/gtest",
   ]
 }
 
 source_set("unit_tests") {
   testonly = true
   sources = [
@@ skipping 20 matching lines @@
 }
 
 if (is_android) {
   # GYP: //component/signin.gypi:investigated_scenario_java
   java_cpp_enum("investigated_scenario_java") {
     sources = [
       "signin_investigator.h",
     ]
   }
 }