Don't accidentally propagate Omaha variable to child processes.

chrome/installer/util/util_constants.cc

Index: chrome/installer/util/util_constants.cc
diff --git a/chrome/installer/util/util_constants.cc b/chrome/installer/util/util_constants.cc
index ef2b07611e16b26f3713b35e99cc7236f840ee89..022cc180bc880a0eb090893b18a914b4a74e5262 100644
--- a/chrome/installer/util/util_constants.cc
+++ b/chrome/installer/util/util_constants.cc
@@ -242,11 +242,6 @@ 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";