[Mac/GN] Add a BUILD.gn file for //chrome/app_shim.

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 146 matching lines @@
 # Template to create a Mac executable application bundle.
 #
 # Arguments
 #
 #     info_plist:
 #         string, path to the Info.plist file that will be used for the bundle.
 #
 #     output_name:
 #         (optional) string, name of the generated app without the
 #         .app suffix. If omitted, defaults to target_name.
+#
+#     extra_configs:
+#         (optional) list of label, additional configs to apply to the
+#         executable target.
 template("mac_app_bundle") {
   assert(defined(invoker.info_plist),
          "The Info.plist file must be specified for $target_name")
 
   _target_name = target_name
   _output_name = target_name
   if (defined(invoker.output_name)) {
     _output_name = invoker.output_name
   }
 
   _executable_target = target_name + "_executable"
   _executable_bundle_data = _executable_target + "_bundle_data"
 
   executable(_executable_target) {
     visibility = [ ":$_executable_bundle_data" ]
     forward_variables_from(invoker,
                            "*",
                            [
                              "assert_no_deps",
                              "data_deps",
                              "info_plist",
                              "output_name",
                              "visibility",
                            ])
+    if (defined(extra_configs)) {
+      configs += extra_configs
+    }
     output_name = _output_name
     output_dir = "$target_out_dir/$_executable_target"
   }
 
   bundle_data(_executable_bundle_data) {
     visibility = [ ":$_target_name" ]
     forward_variables_from(invoker, [ "testonly" ])
     sources = [
       "$target_out_dir/$_executable_target/$_output_name",
     ]
@@ skipping 103 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"
   }
 }