FetchMore functionality backend

components/ntp_snippets/remote/ntp_snippets_fetcher.cc

Index: components/ntp_snippets/remote/ntp_snippets_fetcher.cc
diff --git a/components/ntp_snippets/remote/ntp_snippets_fetcher.cc b/components/ntp_snippets/remote/ntp_snippets_fetcher.cc
index 8e577878ffa620df986580aaed386f777fdc85f4..bde95efc23cce31135e11e86e6f463ce1d62c443 100644
--- a/components/ntp_snippets/remote/ntp_snippets_fetcher.cc
+++ b/components/ntp_snippets/remote/ntp_snippets_fetcher.cc
@@ -316,9 +316,8 @@ NTPSnippetsFetcher::~NTPSnippetsFetcher() {
     token_service_->RemoveObserver(this);
 }
 
-void NTPSnippetsFetcher::SetCallback(
-    const SnippetsAvailableCallback& callback) {
-  snippets_available_callback_ = callback;
+void NTPSnippetsFetcher::SetCallback(SnippetsAvailableCallback callback) {
+  snippets_available_callback_ = std::move(callback);
 }
 
 void NTPSnippetsFetcher::FetchSnippetsFromHosts(
@@ -770,7 +769,7 @@ void NTPSnippetsFetcher::FetchFinished(
 
   DVLOG(1) << "Fetch finished: " << last_status_;
   if (!snippets_available_callback_.is_null())
-    snippets_available_callback_.Run(std::move(fetched_categories));
+    std::move(snippets_available_callback_).Run(std::move(fetched_categories));
 }
 
 bool NTPSnippetsFetcher::DemandQuotaForRequest(bool interactive_request) {