Introduces a search term extraction mechanism working for arbitrary search providers.

chrome/browser/policy/configuration_policy_handler.h

Index: chrome/browser/policy/configuration_policy_handler.h
diff --git a/chrome/browser/policy/configuration_policy_handler.h b/chrome/browser/policy/configuration_policy_handler.h
index 040380878fc50301228b5bff2c5bb9ad5b17d4ba..b292cb3495c0f367bd606ca54e62c1295cec6f08 100644
--- a/chrome/browser/policy/configuration_policy_handler.h
+++ b/chrome/browser/policy/configuration_policy_handler.h
@@ -285,10 +285,14 @@ class DefaultSearchPolicyHandler : public ConfigurationPolicyHandler {
                                const Value** url_value,
                                std::string* url_string);
 
-  // Make sure that the |path| if present in |prefs_|.  If not, set it to
+  // Make sure that the |path| is present in |prefs_|.  If not, set it to
   // a blank string.
   void EnsureStringPrefExists(PrefValueMap* prefs, const std::string& path);
 
+  // Make sure that the |path| is present in |prefs_| and is a ListValue.  If
+  // not, set it to an empty list.
+  void EnsureListPrefExists(PrefValueMap* prefs, const std::string& path);
+
   // The ConfigurationPolicyHandler handlers for each default search policy.
   std::vector<ConfigurationPolicyHandler*> handlers_;