Prototype fix for version shear across updates.

chrome/browser/first_run/upgrade_util_win.h

 // 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.
 
 #ifndef CHROME_BROWSER_FIRST_RUN_UPGRADE_UTIL_WIN_H_
 #define CHROME_BROWSER_FIRST_RUN_UPGRADE_UTIL_WIN_H_
 
 namespace base {
 class CommandLine;
 }
 
 namespace upgrade_util {
 
 // If the new_chrome.exe exists (placed by the installer then is swapped
 // to chrome.exe and the old chrome is renamed to old_chrome.exe. If there
 // is no new_chrome.exe or the swap fails the return is false;
 bool SwapNewChromeExeIfPresent();
 
+// Returns true if the currently running chrome.exe has been renamed to
+// old_chrome.exe. This means that the running executable is out of date and
+// has been renamed by the in-use update process. old_chrome.exe shouldn't
+// continue on and run as the browser process since it may end up launching
+// newer chrome.exes as child processes resulting in a version mismatch.
+bool IsRunningOldChrome();
+
 // Combines the two methods, RelaunchChromeBrowser and
 // SwapNewChromeExeIfPresent, to perform the rename and relaunch of
 // the browser. Note that relaunch does NOT exit the existing browser process.
 // If this is called before message loop is executed, simply exit the main
 // function. If browser is already running, you will need to exit it.
 bool DoUpgradeTasks(const base::CommandLine& command_line);
 
 }  // namespace upgrade_util
 
 #endif  // CHROME_BROWSER_FIRST_RUN_UPGRADE_UTIL_WIN_H_