Delete from Sync the artificial search engines created by the omnibox extensions.

chrome/browser/search_engines/chrome_template_url_service_client.h

Index: chrome/browser/search_engines/chrome_template_url_service_client.h
diff --git a/chrome/browser/search_engines/chrome_template_url_service_client.h b/chrome/browser/search_engines/chrome_template_url_service_client.h
index 03c590362dcd5ec38991bb54c9656b52d7767f54..de0bfbfeed9078b80507a05822d796ac038dbeeb 100644
--- a/chrome/browser/search_engines/chrome_template_url_service_client.h
+++ b/chrome/browser/search_engines/chrome_template_url_service_client.h
@@ -31,7 +31,7 @@ class ChromeTemplateURLServiceClient : public TemplateURLServiceClient,
                                    TemplateURLID id,
                                    const base::string16& term) override;
   void AddKeywordGeneratedVisit(const GURL& url) override;
-  void RestoreExtensionInfoIfNecessary(TemplateURL* template_url) override;
+  bool IsOmniboxExtensionURL(const std::string& url) override;
 
   // history::HistoryServiceObserver:
   void OnURLVisited(history::HistoryService* history_service,