Re-apply r23841 "During uninstall if Chrome is set as default"

chrome/installer/util/shell_util.h

Index: chrome/installer/util/shell_util.h
diff --git a/chrome/installer/util/shell_util.h b/chrome/installer/util/shell_util.h
index ca6eac71967f4609379d3aec40ba9d82693455b7..99f88b88ba34c2b09044da55e090fe5d3a26d93c 100644
--- a/chrome/installer/util/shell_util.h
+++ b/chrome/installer/util/shell_util.h
@@ -10,6 +10,7 @@
 #define CHROME_INSTALLER_UTIL_SHELL_UTIL_H_
 
 #include <windows.h>
+#include <map>
 #include <string>
 
 #include "base/basictypes.h"
@@ -139,6 +140,11 @@ class ShellUtil {
   // User's profile only affects any new user profiles (not existing ones).
   static bool GetQuickLaunchPath(bool system_level, std::wstring* path);
 
+  // Gets a mapping of all registered browser (on local machine) names and
+  // thier reinstall command (which usually sets browser as default).
+  static void GetRegisteredBrowsers(std::map<std::wstring,
+                                    std::wstring>* browsers);
+
   // This function gets a suffix (user's login name) that can be added
   // to Chromium default browser entry in the registry to create a unique name
   // if there are multiple users on the machine, each with their own copy of