Remove duplicated user_prefs::TestingPrefServiceSyncable

components/ntp_tiles/BUILD.gn

 # Copyright 2016 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")
 }
 
 static_library("ntp_tiles") {
   sources = [
@@ skipping 70 matching lines @@
     "popular_sites_unittest.cc",
   ]
 
   deps = [
     ":json_unsafe_parser",
     ":ntp_tiles",
     "//base/test:test_support",
     "//components/favicon/core",
     "//components/favicon_base",
     "//components/image_fetcher",
-    "//components/pref_registry:test_support",
+    "//components/pref_registry:pref_registry",
+    "//components/sync_preferences:test_support",
     "//net:test_support",
     "//testing/gmock",
     "//testing/gtest",
     "//ui/gfx:test_support",
   ]
 }
 
 if (is_android) {
   java_cpp_enum("ntp_tiles_enums_java") {
     sources = [
       "metrics.h",
       "ntp_tile_source.h",
     ]
   }
 }