Protector adds the default prepopulated engine if it was removed.

chrome/browser/search_engines/template_url_service.h

Index: chrome/browser/search_engines/template_url_service.h
diff --git a/chrome/browser/search_engines/template_url_service.h b/chrome/browser/search_engines/template_url_service.h
index fe76da59f7f8f04ccf25e5cea941baec48e68f2d..d97dcbeb22ce8d16a6a00aeb35d7409c54ff8e86 100644
--- a/chrome/browser/search_engines/template_url_service.h
+++ b/chrome/browser/search_engines/template_url_service.h
@@ -145,6 +145,10 @@ class TemplateURLService : public WebDataServiceConsumer,
   // This fails if the supplied template_url is the default search provider.
   void Remove(const TemplateURL* template_url);
 
+  // Updates the information in |existing_turl| using the information from
+  // |new_values|, but the ID for |existing_turl| is retained.
+  void Update(const TemplateURL* existing_turl, const TemplateURL& new_values);
+
   // Removes all auto-generated keywords that were created in the specified
   // range.
   void RemoveAutoGeneratedBetween(base::Time created_after,