Add support for --critical-update-version to installer.

chrome/installer/util/util_constants.cc

 // Copyright (c) 2011 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.
 
 #include "chrome/installer/util/util_constants.h"
 
 namespace installer {
 
 namespace switches {
 
@@ skipping 24 matching lines @@
 // End GCF ready mode temp opt-out.  This re-enables the GCF user agent
 // modification and detection of headers/meta tags.
 const char kChromeFrameReadyModeEndTempOptOut[] = "ready-mode-end-temp-opt-out";
 
 // Run the installer for Chrome SxS.
 const char kChromeSxS[] = "chrome-sxs";
 
 // Create Desktop and QuickLaunch shortcuts
 const char kCreateAllShortcuts[] = "create-all-shortcuts";
 
+// The version number of an update containing critical fixes, for which an
+// in-use Chrome should be restarted ASAP.
+const char kCriticalUpdateVersion[] = "critical-update-version";
+
 // Delete user profile data. This param is useful only when specified with
 // kUninstall, otherwise it is silently ignored.
 const char kDeleteProfile[] = "delete-profile";
 
 // Disable logging
 const char kDisableLogging[] = "disable-logging";
 
 // Prevent installer from creating desktop shortcuts.
 const char kDoNotCreateShortcuts[] = "do-not-create-shortcuts";
 
@@ skipping 135 matching lines @@
 
 // The presence of this environment variable with a value of 1 implies that
 // we should run as a system installation regardless of what is on the
 // command line.
 const char kGoogleUpdateIsMachineEnvVar[] = "GoogleUpdateIsMachine";
 
 const wchar_t kOptionMultiInstall[] = L"multi-install";
 const wchar_t kOptionReadyMode[] = L"ready-mode";
 
 }  // namespace installer