DO NOT SUBMIT. Implement an XPCService for notifications.

build/config/mac/rules.gni

Index: build/config/mac/rules.gni
diff --git a/build/config/mac/rules.gni b/build/config/mac/rules.gni
index a1c3c2ca16473849aab63d18cf8d05ce57e8d0b3..e9c5ebca05648e5c93c7255ae3bbf1aa25bdf24a 100644
--- a/build/config/mac/rules.gni
+++ b/build/config/mac/rules.gni
@@ -220,6 +220,10 @@ template("mac_framework_bundle") {
 #     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
@@ -227,6 +231,11 @@ template("mac_app_bundle") {
     _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"
 
@@ -338,8 +347,9 @@ template("mac_app_bundle") {
       ":$_info_plist_bundle_data",
       ":$_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"
   }