Added unpacking step

chrome/installer/mac/app/BUILD.gn

 # Copyright 2016 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("//testing/test.gni")
 import("//build/config/mac/rules.gni")
 
 source_set("mac_installer_base") {
   sources = [
     "Downloader.m",
     "NSAlert+ChromeInstallerAdditions.m",
     "NSError+ChromeInstallerAdditions.m",
     "OmahaCommunication.m",
     "OmahaXMLParser.m",
     "OmahaXMLRequest.m",
     "SystemInfo.m",
+    "Unpacker.m",
   ]
+  configs += [ "//build/config/compiler:enable_arc" ]
 }
 
 mac_app_bundle("mac_installer_app") {
   info_plist = "Info.plist"
   extra_substitutions = [ "MACOSX_DEPLOYMENT_TARGET=10.9" ]
   sources = [
     "AppDelegate.m",
     "InstallerWindowController.m",
     "main.m",
   ]
 
   deps = [
     ":mac_installer_base",
     ":mac_installer_xibs",
   ]
 
   libs = [
-    "AppKit.framework",
-    "CoreFoundation.framework",
+    "Cocoa.framework",
+    "DiskArbitration.framework",
+    "Security.framework",
   ]
 }
 
 mac_xib_bundle_data("mac_installer_xibs") {
   sources = [
     "MainMenu.xib",
   ]
 }
 
 test("mac_installer_unittests") {
   sources = [
     "testing/OmahaXMLRequest_test.mm",
     "testing/SystemInfo_test.mm",
+    "testing/Unpacker_test.mm",
   ]
   deps = [
     ":mac_installer_base",
     "//base:base",
     "//base/test:run_all_unittests",
     "//testing/gtest:gtest",
   ]
-  libs = [ "Foundation.framework" ]
+  libs = [
+    "Cocoa.framework",
+    "DiskArbitration.framework",
+    "Security.framework",
+  ]
   data = [
     "testing/requestCheck.dtd",
     "testing/requestSample.xml",
     "testing/responseExample.xml",
   ]
 }