Supply a valid Alert XPC identifier to the canary build

chrome/installer/mac/sign_versioned_dir.sh.in

 #!/bin/bash -p
 
 # Copyright (c) 2012 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.
 
 # Using codesign, sign the contents of the versioned directory. Namely, this
 # includes the framework and helper app. After signing, the signatures are
 # verified.
 
@@ skipping 94 matching lines @@
 app_mode_loader_tmp="$(mktemp -t app_mode_loader)"
 cp "${app_mode_loader}" "${app_mode_loader_tmp}"
 
 codesign_with_options "${app_mode_loader_tmp}" \
                       "${enforcement_flags_helpers}" \
                       "app_mode_loader"
 
 cp "${app_mode_loader_tmp}" "${app_mode_loader}"
 rm -f "${app_mode_loader_tmp}"
 
+xpc_plist="${notification_service}/Contents/Info"
+xpc_bundle_id="$(__CFPREFERENCES_AVOID_DAEMON=1 defaults read \
+    "${xpc_plist}" "CFBundleIdentifier")"
+
 codesign_with_options "${notification_service}" \
                       "${enforcement_flags_helpers}" \
-                      "com.google.Chrome.framework.AlertNotificationService"
+                      "${xpc_bundle_id}"
 
 # Only sign widevine plugin if it is present in the bundle.
 # ${enforcement_flags*} are meaningless for dynamic libraries.
 if [[ -f "${widevine_plugin}" ]]; then
   codesign_with_options "${widevine_plugin}" "" "widevinecdmadapter"
 fi
 
 # The framework is a dylib, so ${enforcement_flags_helpers} are meaningless.
 codesign_with_options "${framework}" "" "com.google.Chrome.framework"
 
 codesign_with_options "${helper_app}" \
                       "${enforcement_flags_app}" \
                       "com.google.Chrome.helper"
 
 if [[ -f "${widevine_plugin}" ]]; then
   codesign_display_and_verify "${widevine_plugin}"
 fi
 
 codesign_display_and_verify "${crashpad_handler}" --deep
 codesign_display_and_verify "${app_mode_loader}" --ignore-resources
 codesign_display_and_verify "${notification_service}" --deep
 # The framework contains KeystoneRegistration.framework, which uses
 # custom resource rules, so use --no-strict to verify.
 codesign_display_and_verify "${framework}" --deep --no-strict
 codesign_display_and_verify "${framework}" --strict
 codesign_display_and_verify "${helper_app}" --deep