Separate version env variable for different distributions.

chrome/installer/util/google_chrome_distribution.h

 // Copyright (c) 2006-2009 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 extends generic BrowserDistribution class to declare Google Chrome
 // specific implementation.
 
 #ifndef CHROME_INSTALLER_UTIL_GOOGLE_CHROME_DISTRIBUTION_H_
 #define CHROME_INSTALLER_UTIL_GOOGLE_CHROME_DISTRIBUTION_H_
 
@@ skipping 58 matching lines @@
   // potential use in the uninstall survey. It must be called before the
   // key returned by GetVersionKey() is deleted.
   virtual std::wstring GetDistributionData(RegKey* key);
 
   virtual std::wstring GetUninstallLinkName();
 
   virtual std::wstring GetUninstallRegPath();
 
   virtual std::wstring GetVersionKey();
 
+  virtual std::wstring GetEnvVersionKey();
+
   virtual void UpdateDiffInstallStatus(bool system_install,
       bool incremental_install, installer_util::InstallStatus install_status);
 
   virtual void LaunchUserExperiment(installer_util::InstallStatus status,
                                     const installer::Version& version,
                                     bool system_install);
 
   // Assuming that the user qualifies, this function performs the inactive user
   // toast experiment. It will use chrome to show the UI and it will record the
   // outcome in the registry.
@@ skipping 29 matching lines @@
   // Returns true if at least one uninstall metric was found in
   // uninstall_metrics_dict, false otherwise.
   virtual bool BuildUninstallMetricsString(
       DictionaryValue* uninstall_metrics_dict, std::wstring* metrics);
 
   // The product ID for Google Update.
   std::wstring product_guid_;
 };
 
 #endif  // CHROME_INSTALLER_UTIL_GOOGLE_CHROME_DISTRIBUTION_H_