NTPSnippets: User locale was not set when user isn't signed in.

BUG=645425

Review-Url: https://codereview.chromium.org/2320423002
Cr-Commit-Position: refs/heads/master@{#417592}

components/ntp_snippets/ntp_snippets_fetcher.cc

@@ -454,6 +454,7 @@ void NTPSnippetsFetcher::FetchSnippetsNonAuthenticated() {
   params.excluded_ids = excluded_ids_;
   params.count_to_fetch = count_to_fetch_;
   params.interactive_request = interactive_request_;
+  params.user_locale = locale_;
   FetchSnippetsImpl(url, std::string(), params.BuildRequest());
 }