Refactor mac signing scripts for development workflow

chrome/installer/mac/variables.sh

+# Copyright 2017 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.
+
+# This signs the main app and helper executable, and enables "rootless"
+# protections. The main app does not use library validation because it has to
+# load Flash player, plugins, etc.
+enforcement_flags_app="restrict"
+
+# All the helpers (crashpad, app_mode_loader, etc.), run under library
+# validation as they should not run any code not signed by Google.
+enforcement_flags_helpers="${enforcement_flags_app},library"
+
+# The installer tools are signed with the kill bit as well, as they run on
+# signing machines and should never be modified.
+enforcement_flags_installer_tools="${enforcement_flags_helpers},kill"
+
+# The designated requirement suffix used when signing Chrome's binaries. It
+# contains the hash of the certificate used to sign Chrome. When transitioning
+# signing certs, this may include the hash of both the old and new certificate.
+requirement_suffix="\
+and (certificate leaf = H\"85cee8254216185620ddc8851c7a9fc4dfe120ef\" or \
+certificate leaf = H\"c9a99324ca3fcb23dbcc36bd5fd4f9753305130a\") \
+"