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

chrome/installer/util/package_properties.cc

Index: chrome/installer/util/package_properties.cc
===================================================================
--- chrome/installer/util/package_properties.cc	(revision 70612)
+++ chrome/installer/util/package_properties.cc	(working copy)
@@ -1,4 +1,4 @@
-// Copyright (c) 2010 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.
 
@@ -42,6 +42,10 @@
 PackagePropertiesImpl::~PackagePropertiesImpl() {
 }
 
+const std::wstring& PackagePropertiesImpl::GetAppGuid() {
+  return guid_;
+}
+
 const std::wstring& PackagePropertiesImpl::GetStateKey() {
   return state_key_;
 }