Enable RL sync by default on iOS

ios/chrome/browser/reading_list/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.
 
 source_set("reading_list") {
   sources = [
     "offline_url_utils.cc",
     "offline_url_utils.h",
     "reading_list_download_service.cc",
     "reading_list_download_service.h",
@@ skipping 14 matching lines @@
     "reading_list_web_state_observer.mm",
     "url_downloader.cc",
     "url_downloader.h",
   ]
   deps = [
     "//base",
     "//components/keyed_service/core",
     "//components/keyed_service/ios",
     "//components/pref_registry",
     "//components/prefs",
-    "//components/reading_list",
+    "//components/reading_list/core",
+    "//components/reading_list/ios",
     "//ios/chrome/browser",
     "//ios/chrome/browser/browser_state",
     "//ios/web",
     "//net",
     "//url",
   ]
   public_deps = [
     "//ios/chrome/browser/dom_distiller",
   ]
 }
 
 source_set("unit_tests") {
   testonly = true
   sources = [
     "offline_url_utils_unittest.cc",
     "url_downloader_unittest.cc",
   ]
   deps = [
     ":reading_list",
     "//base",
     "//base/test:test_support",
-    "//components/reading_list",
+    "//components/reading_list/ios",
     "//ios/chrome/browser",
     "//ios/chrome/browser/dom_distiller",
     "//ios/web:test_support",
     "//testing/gtest",
     "//url",
   ]
 }