Transfer responsibility for providing a close button for a notification to each implementation of M…

ui/message_center/views/custom_notification_view.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_MESSAGE_CENTER_VIEWS_CUSTOM_NOTIFICATION_VIEW_H_
 #define UI_MESSAGE_CENTER_VIEWS_CUSTOM_NOTIFICATION_VIEW_H_
 
 #include "base/macros.h"
 #include "ui/message_center/message_center_export.h"
 #include "ui/message_center/views/message_view.h"
 
 namespace message_center {
 
 // View for notification with NOTIFICATION_TYPE_CUSTOM that hosts the custom
 // content of the notification.
 class MESSAGE_CENTER_EXPORT CustomNotificationView : public MessageView {
  public:
   CustomNotificationView(MessageCenterController* controller,
                          const Notification& notification);
   ~CustomNotificationView() override;
 
   // Overidden from MessageView:
   void SetDrawBackgroundAsActive(bool active) override;
+  bool IsCloseButtonFocused() const override;
+  void RequestFocusOnCloseButton() override;
+  bool IsPinned() const override;
 
   // Overridden from views::View:
   gfx::Size GetPreferredSize() const override;
   void Layout() override;
 
  private:
   friend class CustomNotificationViewTest;
 
   // The view for the custom content. Owned by view hierarchy.
   views::View* contents_view_ = nullptr;
+  std::unique_ptr<CustomNotificationContentViewDelegate>
+      contents_view_delegate_;
 
   DISALLOW_COPY_AND_ASSIGN(CustomNotificationView);
 };
 
 }  // namespace message_center
 
 #endif  // UI_MESSAGE_CENTER_VIEWS_CUSTOM_NOTIFICATION_VIEW_H_