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

ios/chrome/browser/search_engines/template_url_service_client_impl.cc

Index: ios/chrome/browser/search_engines/template_url_service_client_impl.cc
diff --git a/ios/chrome/browser/search_engines/template_url_service_client_impl.cc b/ios/chrome/browser/search_engines/template_url_service_client_impl.cc
index 04215a2dfc860704335ec2c68dda5558c6838326..5e8f3c2e2b6a61b1b1e01e99d162445f8f8f0a5c 100644
--- a/ios/chrome/browser/search_engines/template_url_service_client_impl.cc
+++ b/ios/chrome/browser/search_engines/template_url_service_client_impl.cc
@@ -68,9 +68,10 @@ void TemplateURLServiceClientImpl::AddKeywordGeneratedVisit(const GURL& url) {
   }
 }
 
-void TemplateURLServiceClientImpl::RestoreExtensionInfoIfNecessary(
-    TemplateURL* template_url) {
-  // iOS does not supports extension, nothing to do.
+bool TemplateURLServiceClientImpl::IsOmniboxExtensionURL(
+    const std::string& url) {
+  // iOS does not support extensions.
+  return false;
 }
 
 void TemplateURLServiceClientImpl::OnURLVisited(