Revert of Deprecate native and extension notification delegates.

chrome/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.
 
 import("//build/config/chrome_build.gni")
 import("//build/config/crypto.gni")
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
 import("//build/split_static_library.gni")
 import("//chrome/common/features.gni")
@@ skipping 742 matching lines @@
     "net/url_info.h",
     "net_benchmarking.cc",
     "net_benchmarking.h",
     "notifications/alert_dispatcher_mac.h",
     "notifications/desktop_notification_profile_util.cc",
     "notifications/desktop_notification_profile_util.h",
     "notifications/login_state_notification_blocker_chromeos.cc",
     "notifications/login_state_notification_blocker_chromeos.h",
     "notifications/message_center_display_service.cc",
     "notifications/message_center_display_service.h",
+    "notifications/native_notification_delegate.cc",
+    "notifications/native_notification_delegate.h",
     "notifications/native_notification_display_service.cc",
     "notifications/native_notification_display_service.h",
     "notifications/non_persistent_notification_handler.cc",
     "notifications/non_persistent_notification_handler.h",
     "notifications/notification.cc",
     "notifications/notification.h",
     "notifications/notification_channels_provider_android.cc",
     "notifications/notification_channels_provider_android.h",
     "notifications/notification_common.cc",
     "notifications/notification_common.h",
@@ skipping 4007 matching lines @@
       "//components/search_engines",
       "//rlz:rlz_lib",
     ]
   }
 }
 
 service_manifest("preferences_forwarder_manifest") {
   name = "preferences_forwarder"
   source = "prefs/forwarder_manifest.json"
 }