DO NOT SUBMIT. Implement an XPCService for notifications.

build/config/mac/rules.gni

 # Copyright 2015 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/mac/base_rules.gni")
 
 # Generates Info.plist files for Mac apps and frameworks.
 #
 # Arguments
 #
@@ skipping 202 matching lines @@
 #     extra_configs:
 #         (optional) list of label, additional configs to apply to the
 #         executable target.
 #
 #     remove_configs:
 #         (optional) list of label, default configs to remove from the target.
 #
 #     extra_substitutions:
 #         (optional) string array, 'key=value' pairs for extra fields which are
 #         specified in a source Info.plist template.
+#
+#     bundle_extension:
+#         (optional) string, if specified, the bundle extension to use. The
+#         default is "app".
 template("mac_app_bundle") {
   _target_name = target_name
   _output_name = target_name
   if (defined(invoker.output_name)) {
     _output_name = invoker.output_name
   }
 
+  _bundle_extension = "app"
+  if (defined(invoker.bundle_extension)) {
+    _bundle_extension = invoker.bundle_extension
+  }
+
   _executable_target = target_name + "_executable"
   _executable_bundle_data = _executable_target + "_bundle_data"
 
   _info_plist_target = target_name + "_info_plist"
 
   mac_info_plist(_info_plist_target) {
     executable_name = _output_name
     forward_variables_from(invoker,
                            [
                              "extra_substitutions",
@@ skipping 91 matching lines @@
                              "testonly",
                            ])
     if (!defined(deps)) {
       deps = []
     }
     deps += [
       ":$_executable_bundle_data",
       ":$_info_plist_bundle_data",
       ":$_pkg_info_bundle_data",
     ]
-    product_type = "com.apple.product-type.application"
-    bundle_root_dir = "$root_out_dir/${_output_name}.app/Contents"
+
+    bundle_root_dir =
+        "$root_out_dir/${_output_name}.${_bundle_extension}/Contents"
     bundle_resources_dir = "$bundle_root_dir/Resources"
     bundle_executable_dir = "$bundle_root_dir/MacOS"
   }
 }
 
 # Template to package a loadable_module into a .plugin bundle.
 #
 # This takes no extra arguments that differ from a loadable_module.
 template("mac_plugin_bundle") {
   assert(defined(invoker.deps),
@@ skipping 47 matching lines @@
                            ])
     if (!defined(deps)) {
       deps = []
     }
     deps += [ ":$_loadable_module_bundle_data" ]
 
     bundle_root_dir = "$root_out_dir/$_output_name.plugin/Contents"
     bundle_executable_dir = "$bundle_root_dir/MacOS"
   }
 }