Support notifications with custom content

ui/message_center/views/custom_notification_view.h

Index: ui/message_center/views/custom_notification_view.h
diff --git a/ui/message_center/views/custom_notification_view.h b/ui/message_center/views/custom_notification_view.h
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+++ b/ui/message_center/views/custom_notification_view.h
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+// 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;
+
+  // 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;
+
+  DISALLOW_COPY_AND_ASSIGN(CustomNotificationView);
+};
+
+}  // namespace message_center
+
+#endif  // UI_MESSAGE_CENTER_VIEWS_CUSTOM_NOTIFICATION_VIEW_H_