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/memory/ptr_util.h"
+#include "base/memory/weak_ptr.h"
+#include "ui/arc/notification/arc_notification_item.h"
+#include "ui/message_center/notification_delegate.h"
+
+namespace arc {
+
+class ArcNotificationDelegate : public message_center::NotificationDelegate {

[hidehiko, 2017/05/01 12:29:17]

Document about this class?

[yoshiki, 2017/05/08 06:24:52]

Done.

+ public:
+  explicit ArcNotificationDelegate(base::WeakPtr<ArcNotificationItem> item);
+
+  std::unique_ptr<message_center::CustomContent> CreateCustomContent() override;

[hidehiko, 2017/05/01 12:29:17]

// message_center::NotificationDelegate overrides:

for consistency?

[yoshiki, 2017/05/08 06:24:52]

Done.

+  void Close(bool by_user) override;
+  void Click() override;
+
+ private:
+  // The destructor is private since this class is ref-counted.
+  ~ArcNotificationDelegate() override;
+
+  base::WeakPtr<ArcNotificationItem> item_;

[hidehiko, 2017/05/01 12:29:17]

You use WeakPtr here, but all methods assumes (DCHECKs) item_ is alive.
When is WeakPtr actually needed?

[yoshiki, 2017/05/08 06:24:52]

I want to keep the weak ptr to detect a potential use-after-free.

[hidehiko, 2017/05/08 09:34:41]

I see. Would you mind to comment the goal of WeakPtr usage?

+
+  DISALLOW_COPY_AND_ASSIGN(ArcNotificationDelegate);

[hidehiko, 2017/05/01 12:29:17]

missing base/macros.h

[yoshiki, 2017/05/08 06:24:53]

Done.

+};
+
+}  // namespace arc
+
+#endif  // UI_ARC_NOTIFICATION_ARC_CUSTOM_DELEGATE_H_