Duplicate setup.exe into an identical executable and point Active Setup to that executable instead.

chrome/installer/util/installer_state.h

 // Copyright (c) 2012 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.
 
 #ifndef CHROME_INSTALLER_UTIL_INSTALLER_STATE_H_
 #define CHROME_INSTALLER_UTIL_INSTALLER_STATE_H_
 
 #include <set>
 #include <string>
 #include <vector>
@@ skipping 187 matching lines @@
   // Update.  The InstallerResult value is set to 0 (SUCCESS) or 1
   // (FAILED_CUSTOM_ERROR) depending on whether |status| maps to success or not.
   // |status| itself is written to the InstallerError value.
   // |string_resource_id|, if non-zero, identifies a localized string written to
   // the InstallerResultUIString value.  |launch_cmd|, if non-NULL and
   // non-empty, is written to the InstallerSuccessLaunchCmdLine value.
   void WriteInstallerResult(InstallStatus status,
                             int string_resource_id,
                             const std::wstring* launch_cmd) const;
 
+  // Returns true if this install needs to register an Active Setup command.
+  bool RequiresActiveSetup() const;
+
  protected:
   // Returns true if |file| exists and cannot be opened for exclusive write
   // access.
   static bool IsFileInUse(const FilePath& file);
 
   FilePath GetDefaultProductInstallPath(BrowserDistribution* dist) const;
   bool CanAddProduct(const Product& product, const FilePath* product_dir) const;
   Product* AddProductInDirectory(const FilePath* product_dir,
                                  scoped_ptr<Product>* product);
   Product* AddProductFromPreferences(
@@ skipping 31 matching lines @@
   bool verbose_logging_;
   bool ensure_google_update_present_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(InstallerState);
 };  // class InstallerState
 
 }  // namespace installer
 
 #endif  // CHROME_INSTALLER_UTIL_INSTALLER_STATE_H_