Ability to add ResponseProvider

ios/web/public/test/http_server_util.mm

 // Copyright 2016 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.
 
 #include "ios/web/public/test/http_server_util.h"
 
 #include "base/memory/ptr_util.h"
 #include "base/path_service.h"
 #import "ios/web/public/test/http_server.h"
 #include "ios/web/public/test/response_providers/file_based_response_provider.h"
@@ skipping 13 matching lines @@
 }
 
 void SetUpHttpServer(std::unique_ptr<web::ResponseProvider> provider) {
   web::test::HttpServer& server = web::test::HttpServer::GetSharedInstance();
   DCHECK(server.IsRunning());
 
   server.RemoveAllResponseProviders();
   server.AddResponseProvider(std::move(provider));
 }
 
+void AddResponseProvider(std::unique_ptr<web::ResponseProvider> provider) {
+  web::test::HttpServer& server = web::test::HttpServer::GetSharedInstance();
+  DCHECK(server.IsRunning());
+  server.AddResponseProvider(std::move(provider));
+}
+
 }  // namespace test
 }  // namespace web