arc: enable use_new_wrapper_types for notifications.mojom

components/arc/test/fake_notifications_instance.cc

 // 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 "components/arc/test/fake_notifications_instance.h"
 
 namespace arc {
 
 FakeNotificationsInstance::FakeNotificationsInstance() = default;
 FakeNotificationsInstance::~FakeNotificationsInstance() = default;
 
 void FakeNotificationsInstance::SendNotificationEventToAndroid(
-    const mojo::String& key,
+    const std::string& key,
     mojom::ArcNotificationEvent event) {
   events_.emplace_back(key, event);
 }
 
 void FakeNotificationsInstance::CreateNotificationWindow(
-    const mojo::String& key) {}
+    const std::string& key) {}
 
 void FakeNotificationsInstance::CloseNotificationWindow(
-    const mojo::String& key) {}
+    const std::string& key) {}
 
 void FakeNotificationsInstance::Init(mojom::NotificationsHostPtr host_ptr) {}
 
-const std::vector<std::pair<mojo::String, mojom::ArcNotificationEvent>>&
+const std::vector<std::pair<std::string, mojom::ArcNotificationEvent>>&
 FakeNotificationsInstance::events() const {
   return events_;
 }
 
 }  // namespace arc