Don't accidentally propagate Omaha variable to child processes.

chrome/installer/util/util_constants.cc

 // Copyright (c) 2012 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 "chrome/installer/util/util_constants.h"
 
 namespace installer {
 
 namespace switches {
 
@@ skipping 224 matching lines @@
 const wchar_t kUninstallDisplayNameField[] = L"DisplayName";
 const char kUninstallMetricsName[] = "uninstall_metrics";
 const wchar_t kUninstallInstallationDate[] = L"installation_date";
 const wchar_t kInstallerError[] = L"InstallerError";
 const wchar_t kInstallerExtraCode1[] = L"InstallerExtraCode1";
 const wchar_t kInstallerResult[] = L"InstallerResult";
 const wchar_t kInstallerResultUIString[] = L"InstallerResultUIString";
 const wchar_t kInstallerSuccessLaunchCmdLine[] =
     L"InstallerSuccessLaunchCmdLine";
 
-// The presence of this environment variable with a value of 1 implies that
-// we should run as a system installation regardless of what is on the
-// command line.
-const char kGoogleUpdateIsMachineEnvVar[] = "GoogleUpdateIsMachine";
-
 const wchar_t kOptionAppHostIsLauncher[] = L"app-host-is-launcher";
 const wchar_t kOptionMultiInstall[] = L"multi-install";
 const wchar_t kOptionReadyMode[] = L"ready-mode";
 
 // Chrome channel display names.
 const wchar_t kChromeChannelUnknown[] = L"unknown";
 const wchar_t kChromeChannelCanary[] = L"canary";
 const wchar_t kChromeChannelDev[] = L"dev";
 const wchar_t kChromeChannelBeta[] = L"beta";
 const wchar_t kChromeChannelStable[] = L"";
 
 const size_t kMaxAppModelIdLength = 64U;
 
 }  // namespace installer