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

chrome/installer/setup/install_worker.cc

Index: chrome/installer/setup/install_worker.cc
diff --git a/chrome/installer/setup/install_worker.cc b/chrome/installer/setup/install_worker.cc
index 245abc4f53cf4e3b9ec25cfd5a03f91e822e88cc..1e4f915b658ec2807250075b64c39cb32b87fd23 100644
--- a/chrome/installer/setup/install_worker.cc
+++ b/chrome/installer/setup/install_worker.cc
@@ -1111,8 +1111,8 @@ void AddInstallWorkItems(const InstallationState& original_state,
     AddDelegateExecuteWorkItems(installer_state, target_path, new_version,
                                 product, install_list);
 
-    AddActiveSetupWorkItems(installer_state, setup_path, new_version, product,
-                            install_list);
+    AddActiveSetupWorkItems(installer_state, setup_path, temp_path, new_version,
+                            product, install_list);
   }
 
   // Add any remaining work items that involve special settings for
@@ -1387,6 +1387,7 @@ void AddDelegateExecuteWorkItems(const InstallerState& installer_state,
 
 void AddActiveSetupWorkItems(const InstallerState& installer_state,
                              const FilePath& setup_path,
+                             const FilePath& temp_path,
                              const Version& new_version,
                              const Product& product,
                              WorkItemList* list) {
@@ -1405,13 +1406,18 @@ void AddActiveSetupWorkItems(const InstallerState& installer_state,
   const string16 active_setup_path(
       InstallUtil::GetActiveSetupPath(distribution));
 
+  FilePath active_setup_exe(installer_state.GetInstallerDirectory(new_version)
+      .Append(kActiveSetupExe));
+  VLOG(1) << "Adding copy items for " << active_setup_exe.value();
+  list->AddCopyTreeWorkItem(setup_path.value(), active_setup_exe.value(),
+                            temp_path.value(), WorkItem::ALWAYS);
+
   VLOG(1) << "Adding registration items for Active Setup.";
   list->AddCreateRegKeyWorkItem(root, active_setup_path);
   list->AddSetRegValueWorkItem(root, active_setup_path, L"",
                                distribution->GetAppShortCutName(), true);
 
-  CommandLine cmd(installer_state.GetInstallerDirectory(new_version).
-      Append(setup_path.BaseName()));
+  CommandLine cmd(active_setup_exe);
   cmd.AppendSwitch(installer::switches::kConfigureUserSettings);
   cmd.AppendSwitch(installer::switches::kVerboseLogging);
   cmd.AppendSwitch(installer::switches::kSystemLevel);