Revert of Make extensions DSE persistent in browser prefs

components/search_engines/template_url_service.h

Index: components/search_engines/template_url_service.h
diff --git a/components/search_engines/template_url_service.h b/components/search_engines/template_url_service.h
index d7e4e87f86da093b1584bb35e6e9d387e07fad97..d56bb8d90d070e04e7e3048ec19281438df0b6f1 100644
--- a/components/search_engines/template_url_service.h
+++ b/components/search_engines/template_url_service.h
@@ -708,6 +708,13 @@
   TemplateURL* FindMatchingExtensionTemplateURL(const TemplateURLData& data,
                                                 TemplateURL::Type type);
 
+  // Finds the most recently-installed NORMAL_CONTROLLED_BY_EXTENSION engine
+  // that supports replacement and wants to be default, if any. Notifies the
+  // DefaultSearchManager, which might change the effective default search
+  // engine.
+  void UpdateExtensionDefaultSearchEngine();
+
+
   // ---------- Browser state related members ---------------------------------
   PrefService* prefs_;