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..fa8fde4673348f5c4331d844e675858b39fae557 100644
--- a/chrome/installer/setup/install_worker.cc
+++ b/chrome/installer/setup/install_worker.cc
@@ -108,6 +108,13 @@ void GetIELowRightsElevationPolicyKeyPath(ElevationPolicyId policy,
   }
 }
 
+// Returns true if this install (as described by |installer_state|) requires
+// Active Setup.
+bool RequiresActiveSetup(const InstallerState& installer_state) {

[grt (UTC plus 2), 2013/01/09 18:57:45]

did you consider making this a method on InstallerState?

[gab, 2013/01/09 19:35:10]

Arg...! Sorry for wasting your time, this is what I intended to do and somehow
didn't do...

Done.

+  return (installer_state.FindProduct(BrowserDistribution::CHROME_BROWSER) &&
+          installer_state.system_install());
+}
+
 // Local helper to call AddRegisterComDllWorkItems for all DLLs in a set of
 // products managed by a given package.
 // |old_version| can be NULL to indicate no Chrome is currently installed.
@@ -168,6 +175,13 @@ void AddInstallerCopyTasks(const InstallerState& installer_state,
                                       temp_path.value(), WorkItem::ALWAYS);
   }
 
+  if (RequiresActiveSetup(installer_state)) {
+    FilePath active_setup_exe(installer_dir.Append(kActiveSetupExe));

[grt (UTC plus 2), 2013/01/09 18:57:45]

suggested comment:
    // Make a copy of setup.exe with a different name so that Active Setup
    // doesn't require an admin on XP thanks to Application Compatibility.

[gab, 2013/01/09 19:35:10]

Done.

+    install_list->AddCopyTreeWorkItem(
+        setup_path.value(), active_setup_exe.value(), temp_path.value(),
+        WorkItem::ALWAYS);
+  }
+
   // If only the App Host (not even the Chrome Binaries) is being installed,
   // this must be a user-level App Host piggybacking on system-level Chrome
   // Binaries. Only setup.exe is required, and only for uninstall.
@@ -1400,6 +1414,7 @@ void AddActiveSetupWorkItems(const InstallerState& installer_state,
             << "-level " << distribution->GetAppShortCutName();
     return;
   }
+  DCHECK(RequiresActiveSetup(installer_state));

[robertshield, 2013/01/09 18:53:14]

Doesn't this check duplicate that done in the if statement immediately above?

[gab, 2013/01/09 18:56:35]

Right, but as discussed with Greg, putting it here so that anyone eventually
calling this for another product would hit this if they fail to also modify
RequiresActiveSetup().

RequiresActiveSetup() itself though can't replace the above condition as
RequiresActiveSetup() is generic for the entire installer_state and
AddActiveSetupWorkItems() is called per-product.

 
   const HKEY root = HKEY_LOCAL_MACHINE;
   const string16 active_setup_path(
@@ -1410,8 +1425,9 @@ void AddActiveSetupWorkItems(const InstallerState& installer_state,
   list->AddSetRegValueWorkItem(root, active_setup_path, L"",
                                distribution->GetAppShortCutName(), true);
 
-  CommandLine cmd(installer_state.GetInstallerDirectory(new_version).
-      Append(setup_path.BaseName()));
+  FilePath active_setup_exe(installer_state.GetInstallerDirectory(new_version)
+      .Append(kActiveSetupExe));
+  CommandLine cmd(active_setup_exe);
   cmd.AppendSwitch(installer::switches::kConfigureUserSettings);
   cmd.AppendSwitch(installer::switches::kVerboseLogging);
   cmd.AppendSwitch(installer::switches::kSystemLevel);