Merge ArcNotificationItem and ArcCustomNotificationItem

ui/arc/notification/arc_notification_delegate.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_CUSTOM_DELEGATE_H_
+#define UI_ARC_NOTIFICATION_ARC_CUSTOM_DELEGATE_H_
+
+#include "base/macros.h"
+#include "base/memory/weak_ptr.h"
+#include "ui/message_center/notification_delegate.h"
+
+namespace arc {
+
+class ArcNotificationItem;
+
+/*
+ * Implementation of NotificationDelegate for ARC notifications.
+ */
+class ArcNotificationDelegate : public message_center::NotificationDelegate {
+ public:
+  explicit ArcNotificationDelegate(base::WeakPtr<ArcNotificationItem> item);
+
+  // message_center::NotificationDelegate overrides:
+  std::unique_ptr<message_center::CustomContent> CreateCustomContent() override;
+  void Close(bool by_user) override;
+  void Click() override;
+
+ private:
+  // The destructor is private since this class is ref-counted.
+  ~ArcNotificationDelegate() override;
+
+  // We use weak ptr to detect potential use-after-free. The lives of objects
+  // around ARC notification is somewhat complex so we want to use it until
+  // it gets stable.
+  base::WeakPtr<ArcNotificationItem> item_;
+
+  DISALLOW_COPY_AND_ASSIGN(ArcNotificationDelegate);
+};
+
+}  // namespace arc
+
+#endif  // UI_ARC_NOTIFICATION_ARC_CUSTOM_DELEGATE_H_