Plumb notification action index for desktop SW notificationclick

chrome/browser/notifications/persistent_notification_delegate.h

 // Copyright 2014 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.
 
 #ifndef CHROME_BROWSER_NOTIFICATIONS_PERSISTENT_NOTIFICATION_DELEGATE_H_
 #define CHROME_BROWSER_NOTIFICATIONS_PERSISTENT_NOTIFICATION_DELEGATE_H_
 
 #include <stdint.h>
 #include <string>
 
@@ skipping 17 matching lines @@
   // Persistent id of this notification in the notification database. To be
   // used when retrieving all information associated with it.
   int64_t persistent_notification_id() const {
     return persistent_notification_id_;
   }
 
   // NotificationDelegate implementation.
   void Display() override;
   void Close(bool by_user) override;
   void Click() override;
+  void ButtonClick(int button_index) override;
   std::string id() const override;
 
  protected:
   ~PersistentNotificationDelegate() override;
 
  private:
   content::BrowserContext* browser_context_;
   int64_t persistent_notification_id_;
   GURL origin_;
 
   std::string id_;
 };
 
 #endif  // CHROME_BROWSER_NOTIFICATIONS_PERSISTENT_NOTIFICATION_DELEGATE_H_