[Remote suggestions] Remove the unique_ptr wrapper around callbacks

chrome/browser/ui/webui/snippets_internals_message_handler.cc

Index: chrome/browser/ui/webui/snippets_internals_message_handler.cc
diff --git a/chrome/browser/ui/webui/snippets_internals_message_handler.cc b/chrome/browser/ui/webui/snippets_internals_message_handler.cc
index b393b588a5eec393b420acfc99446eeb23eef2ff..9b7798098caa38115c50019ad18ed5fc5be22f83 100644
--- a/chrome/browser/ui/webui/snippets_internals_message_handler.cc
+++ b/chrome/browser/ui/webui/snippets_internals_message_handler.cc
@@ -314,7 +314,8 @@ void SnippetsInternalsMessageHandler::ClearClassification(
 void SnippetsInternalsMessageHandler::FetchRemoteSuggestionsInTheBackground(
     const base::ListValue* args) {
   DCHECK_EQ(0u, args->GetSize());
-  remote_suggestions_provider_->RefetchInTheBackground(nullptr);
+  remote_suggestions_provider_->RefetchInTheBackground(
+      RemoteSuggestionsProvider::FetchStatusCallback());
 }
 
 void SnippetsInternalsMessageHandler::SendAllContent() {