Return Windows error code when create-process fails.

chrome/installer/setup/BUILD.gn

 # 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("//testing/test.gni")
 
 if (is_win) {
   test("setup_unittests") {
     # TODO(robertshield): Move the items marked with "Move to lib"
     # below into a separate lib and then link both setup.exe and
     # setup_unittests.exe against that.
     sources = [
       "../mini_installer/appid.h",
       "../mini_installer/chrome.release",  # Move to lib
       "../mini_installer/chrome_appid.cc",
       "../mini_installer/configuration.cc",
       "../mini_installer/configuration.h",
       "../mini_installer/configuration_test.cc",
       "../mini_installer/decompress.cc",
       "../mini_installer/decompress.h",
       "../mini_installer/decompress_test.cc",
+      "../mini_installer/mini_installer_constants.cc",
+      "../mini_installer/mini_installer_constants.h",
       "../mini_installer/mini_string.cc",
       "../mini_installer/mini_string.h",
       "../mini_installer/mini_string_test.cc",
+      "../mini_installer/regkey.cc",
+      "../mini_installer/regkey.h",
       "app_launcher_installer.cc",  # Move to lib
       "app_launcher_installer.h",  # Move to lib
       "archive_patch_helper.cc",  # Move to lib
       "archive_patch_helper.h",  # Move to lib
       "archive_patch_helper_unittest.cc",
       "install.cc",  # Move to lib
       "install.h",  # Move to lib
       "install_unittest.cc",
       "install_worker.cc",  # Move to lib
       "install_worker.h",  # Move to lib
@@ skipping 16 matching lines @@
       "//chrome/installer/util:strings",
       "//chrome/installer/util:util",
       "//testing/gmock",
       "//testing/gtest",
     ]
 
     # TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
     configs += [ "//build/config/compiler:no_size_t_to_int_warning" ]
   }
 }