Applying http://codereview.chromium.org/6156005/ for tommi. Original desc.:...

chrome/installer/setup/setup_main.cc

 // Copyright (c) 2010 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 <windows.h>
 #include <msi.h>
 #include <shellapi.h>
 #include <shlobj.h>
 
 #include <string>
@@ skipping 718 matching lines @@
       return false;
     }
     initialized_ = true;
     return true;
   }
 
  private:
   bool initialized_;
 };
 
-bool PopulateInstallations(const MasterPreferences& prefs,
+bool PopulateInstallations(bool for_uninstall,
+                           const MasterPreferences& prefs,
                            ProductPackageMapping* installations) {
   DCHECK(installations);
   bool success = true;
 
   bool implicit_chrome_install = false;
   bool implicit_gcf_install = false;
 
-  if (prefs.is_multi_install()) {
-    // See what products are already installed in multi mode.
-    // When we do multi installs, we must upgrade all installations
-    // in sync since they share the binaries.
+  // See what products are already installed in multi mode.
+  // When we do multi installs, we must upgrade all installations in sync since
+  // they share the binaries.  Be careful to not do this when we're uninstalling
+  // a product.
+  if (prefs.is_multi_install() && !for_uninstall) {
     struct CheckInstall {
       bool* installed;
       BrowserDistribution::Type type;
     } product_checks[] = {
       {&implicit_chrome_install, BrowserDistribution::CHROME_BROWSER},
       {&implicit_gcf_install, BrowserDistribution::CHROME_FRAME},
     };
 
     for (size_t i = 0; i < arraysize(product_checks); ++i) {
       BrowserDistribution* dist = BrowserDistribution::GetSpecificDistribution(
           product_checks[i].type, prefs);
       *product_checks[i].installed = installer::IsInstalledAsMulti(
           installations->system_level(), dist);
       LOG_IF(INFO, *product_checks[i].installed)
           << "Product already installed and must be included: "
           << dist->GetApplicationName();
     }
   }
 
   if (prefs.install_chrome() || implicit_chrome_install) {
-    VLOG(1) << "Install distribution: Chrome";
+    VLOG(1) << (for_uninstall ? "Uninstall" : "Install")
+            << " distribution: Chrome";
     success = installations->AddDistribution(
         BrowserDistribution::CHROME_BROWSER, prefs);
   }
 
   if (success && (prefs.install_chrome_frame() || implicit_gcf_install)) {
-    VLOG(1) << "Install distribution: Chrome Frame";
+    VLOG(1) << (for_uninstall ? "Uninstall" : "Install")
+            << " distribution: Chrome Frame";
     success = installations->AddDistribution(
         BrowserDistribution::CHROME_FRAME, prefs);
   }
   return success;
 }
 
 // Returns the Custom information for the client identified by the exe path
 // passed in. This information is used for crash reporting.
 google_breakpad::CustomClientInfo* GetCustomInfo(const wchar_t* exe_path) {
   std::wstring product;
@@ skipping 81 matching lines @@
   VLOG(1) << "system install is " << system_install;
 
   google_breakpad::scoped_ptr<google_breakpad::ExceptionHandler> breakpad(
       InitializeCrashReporting(system_install));
 
   InstallationState original_state;
   original_state.Initialize(prefs);
 
   InstallerState installer_state;
   installer_state.Initialize(prefs, original_state);
+  const bool is_uninstall = cmd_line.HasSwitch(installer::switches::kUninstall);
 
   ProductPackageMapping installations(prefs.is_multi_install(), system_install);
-  if (!PopulateInstallations(prefs, &installations)) {
+  if (!PopulateInstallations(is_uninstall, prefs, &installations)) {
     // Currently this can only fail if one of the installations is a multi and
     // a pre-existing single installation exists or vice versa.
     installer::InstallStatus status = installer::NON_MULTI_INSTALLATION_EXISTS;
     int string_id = IDS_INSTALL_NON_MULTI_INSTALLATION_EXISTS_BASE;
     if (!prefs.is_multi_install()) {
       status = installer::MULTI_INSTALLATION_EXISTS;
       string_id = IDS_INSTALL_MULTI_INSTALLATION_EXISTS_BASE;
     }
     LOG(ERROR) << "Failed to populate installations: " << status;
     InstallUtil::WriteInstallerResult(system_install,
@@ skipping 53 matching lines @@
       return exit_code;
     } else {
       LOG(ERROR) << "Non admin user can not install system level Chrome.";
       InstallUtil::WriteInstallerResult(system_install,
           installer_state.state_key(), installer::INSUFFICIENT_RIGHTS,
           IDS_INSTALL_INSUFFICIENT_RIGHTS_BASE, NULL);
       return installer::INSUFFICIENT_RIGHTS;
     }
   }
 
-  bool is_uninstall = cmd_line.HasSwitch(installer::switches::kUninstall);
-
   installer::InstallStatus install_status = installer::UNKNOWN_STATUS;
   // If --uninstall option is given, uninstall chrome
   if (is_uninstall) {
     for (size_t i = 0; i < installations.products().size(); ++i) {
       install_status = UninstallProduct(original_state, installer_state,
           cmd_line, *installations.products()[i]);
     }
   } else {
     // If --uninstall option is not specified, we assume it is install case.
     const Packages& packages = installations.packages();
@@ skipping 37 matching lines @@
       // to pass through, since this is only returned on uninstall which is
       // never invoked directly by Google Update.
       return_code = InstallUtil::GetInstallReturnCode(install_status);
     }
   }
 
   VLOG(1) << "Installation complete, returning: " << return_code;
 
   return return_code;
 }