Fix some problems with machine level install.

chrome/installer/util/browser_distribution.cc

 // Copyright (c) 2006-2008 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.
 //
 // This file defines a class that contains various method related to branding.
 // It provides only default implementations of these methods. Usually to add
 // specific branding, we will need to extend this class with a custom
 // implementation.
 
 #include "chrome/installer/util/browser_distribution.h"
 #include "chrome/installer/util/google_chrome_distribution.h"
 
 BrowserDistribution* BrowserDistribution::GetDistribution() {
   static BrowserDistribution* dist = NULL;
   if (dist == NULL) {
 #if defined(GOOGLE_CHROME_BUILD)
     dist = new GoogleChromeDistribution();
 #else
     dist = new BrowserDistribution();
 #endif
   }
   return dist;
 }
 
 void BrowserDistribution::DoPostUninstallOperations(
     const installer::Version& version) {
 }
 
-void BrowserDistribution::DoPreUninstallOperations() {
-}
-
 std::wstring BrowserDistribution::GetApplicationName() {
   return L"Chromium";
 }
 
 std::wstring BrowserDistribution::GetInstallSubDir() {
   return L"Chromium";
 }
 
 std::wstring BrowserDistribution::GetPublisherName() {
   return L"Chromium";
@@ skipping 13 matching lines @@
 }
 
 std::wstring BrowserDistribution::GetVersionKey() {
   return L"Software\\Chromium";
 }
 
 void BrowserDistribution::UpdateDiffInstallStatus(bool system_install,
     bool incremental_install, installer_util::InstallStatus install_status) {
 }