Allow two user level installs of Chrome to have default browser settings.

chrome/installer/setup/setup_main.cc

 // Copyright (c) 2009 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 <string>
 #include <windows.h>
 #include <msi.h>
 #include <shlobj.h>
 
 #include "base/at_exit.h"
@@ skipping 555 matching lines @@
     return true;;
   } else if (cmd_line.HasSwitch(
       installer_util::switches::kRegisterChromeBrowser)) {
     // If --register-chrome-browser option is specified, register all
     // Chrome protocol/file associations as well as register it as a valid
     // browser for Start Menu->Internet shortcut. This option should only
     // be used when setup.exe is launched with admin rights. We do not
     // make any user specific changes in this option.
     std::wstring chrome_exe(cmd_line.GetSwitchValue(
         installer_util::switches::kRegisterChromeBrowser));
-    exit_code = ShellUtil::AddChromeToSetAccessDefaults(chrome_exe, true);
+    std::wstring suffix;
+    if (cmd_line.HasSwitch(
+        installer_util::switches::kRegisterChromeBrowserSuffix)) {
+      suffix = cmd_line.GetSwitchValue(
+          installer_util::switches::kRegisterChromeBrowserSuffix);
+    }
+    exit_code = ShellUtil::RegisterChromeBrowser(chrome_exe, suffix, false);
     return true;
   } else if (cmd_line.HasSwitch(installer_util::switches::kRenameChromeExe)) {
     // If --rename-chrome-exe is specified, we want to rename the executables
     // and exit.
     exit_code = RenameChromeExecutables(system_install);
     return true;
   } else if (cmd_line.HasSwitch(
       installer_util::switches::kRemoveChromeRegistration)) {
+    // This is almost reverse of --register-chrome-browser option above.
+    // Here we delete Chrome browser registration. This option should only
+    // be used when setup.exe is launched with admin rights. We do not
+    // make any user specific changes in this option.
+    std::wstring suffix;
+    if (cmd_line.HasSwitch(
+        installer_util::switches::kRegisterChromeBrowserSuffix)) {
+      suffix = cmd_line.GetSwitchValue(
+          installer_util::switches::kRegisterChromeBrowserSuffix);
+    }
     installer_util::InstallStatus tmp = installer_util::UNKNOWN_STATUS;
-    installer_setup::DeleteChromeRegistrationKeys(HKEY_LOCAL_MACHINE, tmp);
+    installer_setup::DeleteChromeRegistrationKeys(HKEY_LOCAL_MACHINE,
+                                                  suffix, tmp);
     exit_code = tmp;
     return true;
   } else if (cmd_line.HasSwitch(installer_util::switches::kInactiveUserToast)) {
     // Launch the inactive user toast experiment.
     dist->InactiveUserToastExperiment();
     return true;
   }
   return false;
 }
 
@@ skipping 77 matching lines @@
   } else {
     install_status = InstallChrome(parsed_command_line,
                                    installed_version.get(),
                                    options);
   }
 
   CoUninitialize();
   BrowserDistribution* dist = BrowserDistribution::GetDistribution();
   return dist->GetInstallReturnCode(install_status);
 }