Move message_center::CustomNotificationView to arc::ArcNotificationView

ui/arc/notification/arc_notification_item_impl.h

 // Copyright 2017 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_ITEM_IMPL_H_
 #define UI_ARC_NOTIFICATION_ARC_NOTIFICATION_ITEM_IMPL_H_
 
 #include <memory>
 #include <string>
 
@@ skipping 29 matching lines @@
   void ToggleExpansion() override;
   void AddObserver(Observer* observer) override;
   void RemoveObserver(Observer* observer) override;
   void IncrementWindowRefCount() override;
   void DecrementWindowRefCount() override;
   bool GetPinned() const override;
   const gfx::ImageSkia& GetSnapshot() const override;
   mojom::ArcNotificationExpandState GetExpandState() const override;
   mojom::ArcNotificationShownContents GetShownContents() const override;
   const std::string& GetNotificationKey() const override;
+  const std::string& GetNotificationId() const override;
 
  private:
   // Return true if it's on the thread this instance is created on.
   bool CalledOnValidThread() const;
 
   ArcNotificationManager* const manager_;
   message_center::MessageCenter* const message_center_;
 
   // The pinned state of the latest notification.
   bool pinned_ = false;
@@ skipping 23 matching lines @@
 
   base::ThreadChecker thread_checker_;
   base::WeakPtrFactory<ArcNotificationItemImpl> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ArcNotificationItemImpl);
 };
 
 }  // namespace arc
 
 #endif  // UI_ARC_NOTIFICATION_ARC_NOTIFICATION_ITEM_IMPL_H_