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

ios/chrome/browser/search_engines/template_url_service_client_impl.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef IOS_CHROME_BROWSER_SEARCH_ENGINES_TEMPLATE_URL_SERVICE_CLIENT_IMPL_H_
 #define IOS_CHROME_BROWSER_SEARCH_ENGINES_TEMPLATE_URL_SERVICE_CLIENT_IMPL_H_
 
 #include "base/macros.h"
 #include "components/history/core/browser/history_service_observer.h"
 #include "components/search_engines/template_url_service_client.h"
@@ skipping 17 matching lines @@
 
  private:
   // TemplateURLServiceClient:
   void Shutdown() override;
   void SetOwner(TemplateURLService* owner) override;
   void DeleteAllSearchTermsForKeyword(history::KeywordID keyword_id) override;
   void SetKeywordSearchTermsForURL(const GURL& url,
                                    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,
                     ui::PageTransition transition,
                     const history::URLRow& row,
                     const history::RedirectList& redirects,
                     base::Time visit_time) override;
 
   TemplateURLService* owner_;
   history::HistoryService* history_service_;
 
   DISALLOW_COPY_AND_ASSIGN(TemplateURLServiceClientImpl);
 };
 
 }  // namespace ios
 
 #endif  // IOS_CHROME_BROWSER_SEARCH_ENGINES_TEMPLATE_URL_SERVICE_CLIENT_IMPL_H_