Update checks of multi-installs now use the proper app guid....

chrome/installer/util/helper.h

Index: chrome/installer/util/helper.h
===================================================================
--- chrome/installer/util/helper.h	(revision 70612)
+++ chrome/installer/util/helper.h	(working copy)
@@ -1,4 +1,4 @@
-// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
+// Copyright (c) 2011 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.
 //
@@ -8,6 +8,8 @@
 #define CHROME_INSTALLER_UTIL_HELPER_H_
 #pragma once
 
+#include <string>
+
 class BrowserDistribution;
 class CommandLine;
 class FilePath;
@@ -51,6 +53,10 @@
 FilePath GetChromeFrameInstallPath(bool multi_install, bool system_install,
                                    BrowserDistribution* dist);
 
+// Returns the app guid under which the current process receives updates from
+// Google Update.
+std::wstring GetAppGuidForUpdates(bool system_install);
+
 }  // namespace installer
 
 #endif  // CHROME_INSTALLER_UTIL_HELPER_H_