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

chrome/installer/util/util_constants.cc

 // 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.
 
 #include "chrome/installer/util/util_constants.h"
 
 namespace installer {
 
 namespace switches {
 
@@ skipping 175 matching lines @@
 
 // The group this experiment belongs to.
 const char kExperimentGroup[] = "experiment-group";
 
 // A handle value of the key to write the results of the toast experiment
 // to. See DuplicateGoogleUpdateSystemClientKey for details.
 const char kToastResultsKey[] = "toast-results-key";
 
 }  // namespace switches
 
+// The Active Setup executable will be an identical copy of setup.exe; this is
+// necessary because Windows' installer detection heuristics (which include
+// things like process name being "setup.exe") will otherwise force elevation
+// for non-admin users when setup.exe is launched. This is mitigated by adding
+// requestedExecutionLevel="asInvoker" to setup.exe's manifest on Vista+, but
+// there is no such manifest entry on Windows XP (which results in
+// crbug.com/166473). The name "as.exe" is short and obscur on purpose so that:
+// 1) It is not detected as an installer by any naming-based heuristic.
+// 2) No adventurous user feels like running this will solve his problems (as
+//    something like "user_config.exe" could otherwise suggest).
+// TODO(gab): Rename setup.exe itself altogether and use the same binary for
+// Active Setup.
+const wchar_t kActiveSetupExe[] = L"as.exe";

[grt (UTC plus 2), 2013/01/09 14:13:15]

This name is too short and obscure. How about using whatever name you'd like
setup.exe to have? chromesu.exe (8.3!)?

[gab, 2013/01/09 15:39:42]

sgtm :)!

 const wchar_t kChromeAppHostExe[] = L"app_host.exe";
 const wchar_t kChromeDll[] = L"chrome.dll";
 const wchar_t kChromeExe[] = L"chrome.exe";
 const wchar_t kChromeFrameDll[] = L"npchrome_frame.dll";
 const wchar_t kChromeFrameHelperExe[] = L"chrome_frame_helper.exe";
 const wchar_t kChromeFrameHelperWndClass[] = L"ChromeFrameHelperWindowClass";
 const wchar_t kChromeFrameReadyModeField[] = L"ChromeFrameReadyMode";
 const wchar_t kChromeLauncherExe[] = L"chrome_launcher.exe";
 const wchar_t kChromeNewExe[] = L"new_chrome.exe";
 const wchar_t kChromeOldExe[] = L"old_chrome.exe";
@@ skipping 38 matching lines @@
 // Chrome channel display names.
 const wchar_t kChromeChannelUnknown[] = L"unknown";
 const wchar_t kChromeChannelCanary[] = L"canary";
 const wchar_t kChromeChannelDev[] = L"dev";
 const wchar_t kChromeChannelBeta[] = L"beta";
 const wchar_t kChromeChannelStable[] = L"";
 
 const size_t kMaxAppModelIdLength = 64U;
 
 }  // namespace installer