Split content settings pref related logic into a separate class

components/content_settings/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.
 
 static_library("browser") {
   sources = [
+    "content_settings_binary_value_map.cc",
+    "content_settings_binary_value_map.h",
     "content_settings_client.h",
     "content_settings_default_provider.cc",
     "content_settings_default_provider.h",
     "content_settings_details.cc",
     "content_settings_details.h",
-    "content_settings_binary_value_map.cc",
-    "content_settings_binary_value_map.h",
     "content_settings_observable_provider.cc",
     "content_settings_observable_provider.h",
     "content_settings_observer.h",
     "content_settings_origin_identifier_value_map.cc",
     "content_settings_origin_identifier_value_map.h",
     "content_settings_override_provider.cc",
     "content_settings_override_provider.h",
     "content_settings_policy_provider.cc",
     "content_settings_policy_provider.h",
+    "content_settings_pref.cc",
+    "content_settings_pref.h",
     "content_settings_pref_provider.cc",
     "content_settings_pref_provider.h",
     "content_settings_provider.h",
     "content_settings_rule.cc",
     "content_settings_rule.h",
     "content_settings_usages_state.cc",
     "content_settings_usages_state.h",
     "content_settings_utils.cc",
     "content_settings_utils.h",
     "host_content_settings_map.cc",
@@ skipping 25 matching lines @@
 
   deps = [
     ":browser",
     "//base",
     "//components/content_settings/core/common",
     "//components/content_settings/core/test:test_support",
     "//testing/gtest",
     "//url",
   ]
 }