Add support for native extension notifications

chrome/browser/notifications/non_persistent_notification_handler.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 "chrome/browser/notifications/non_persistent_notification_handler.h"
 
 #include "base/strings/nullable_string16.h"
 #include "chrome/browser/notifications/notification_delegate.h"
 #include "chrome/browser/notifications/platform_notification_service_impl.h"
 
-NonPersistentNotificationHandler::NonPersistentNotificationHandler() {}
-NonPersistentNotificationHandler::~NonPersistentNotificationHandler() {}
+NonPersistentNotificationHandler::NonPersistentNotificationHandler() = default;
+NonPersistentNotificationHandler::~NonPersistentNotificationHandler() = default;
 
 void NonPersistentNotificationHandler::OnClose(
     Profile* profile,
     const std::string& origin,
     const std::string& notification_id,
     bool by_user) {
   if (notifications_.find(notification_id) != notifications_.end()) {
     notifications_[notification_id]->Close(by_user);
     notifications_.erase(notification_id);
   }
 }
 
 void NonPersistentNotificationHandler::OnClick(
     Profile* profile,
     const std::string& origin,
     const std::string& notification_id,
     int action_index,
     const base::NullableString16& reply) {
-  // Buttons and replies not supported for non persistent notifications.
-  DCHECK_EQ(action_index, -1);
   DCHECK(reply.is_null());
 
   if (notifications_.find(notification_id) != notifications_.end()) {
     notifications_[notification_id]->Click();
   }
 }
 
 void NonPersistentNotificationHandler::OpenSettings(Profile* profile) {
   NotificationCommon::OpenNotificationSettings(profile);
 }
 
 void NonPersistentNotificationHandler::RegisterNotification(
     const std::string& notification_id,
     NotificationDelegate* delegate) {
   DCHECK_EQ(notifications_.count(notification_id), 0u);
   notifications_[notification_id] =
       scoped_refptr<NotificationDelegate>(delegate);
 }