Support buttons on ARC Notifications

ui/arc/notification/arc_notification_manager.h

 // 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.
 
 #ifndef UI_ARC_NOTIFICATION_ARC_NOTIFICATION_MANAGER_H_
 #define UI_ARC_NOTIFICATION_ARC_NOTIFICATION_MANAGER_H_
 
 #include <map>
 #include <string>
 
@@ skipping 19 matching lines @@
   // ArcBridgeService::Observer implementation:
   void OnNotificationsInstanceReady() override;
 
   // NotificationsHost implementation:
   void OnNotificationPosted(ArcNotificationDataPtr data) override;
   void OnNotificationRemoved(const mojo::String& key) override;
 
   // Methods called from ArcNotificationItem:
   void SendNotificationRemovedFromChrome(const std::string& key);
   void SendNotificationClickedOnChrome(const std::string& key);
+  void SendNotificationButtonClickedOnChrome(
+      const std::string& key, int button_index);
 
  private:
   const AccountId main_profile_id_;
 
   using ItemMap =
       base::ScopedPtrHashMap<std::string, scoped_ptr<ArcNotificationItem>>;
   ItemMap items_;
 
   mojo::Binding<arc::NotificationsHost> binding_;
 
   DISALLOW_COPY_AND_ASSIGN(ArcNotificationManager);
 };
 
 }  // namespace arc
 
 #endif  // UI_ARC_NOTIFICATION_ARC_NOTIFICATION_MANAGER_H_