arc: Show custom notification via notification surface

ui/arc/notification/arc_custom_notification_view.h

Index: ui/arc/notification/arc_custom_notification_view.h
diff --git a/ui/arc/notification/arc_custom_notification_view.h b/ui/arc/notification/arc_custom_notification_view.h
new file mode 100644
index 0000000000000000000000000000000000000000..8effae750c650af98fb7a5ed76ef4008f1e32829
--- /dev/null
+++ b/ui/arc/notification/arc_custom_notification_view.h
@@ -0,0 +1,36 @@
+// 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_ARC_NOTIFICATION_ARC_CUSTOM_NOTIFICATION_VIEW_H_
+#define UI_ARC_NOTIFICATION_ARC_CUSTOM_NOTIFICATION_VIEW_H_
+
+#include <string>
+
+#include "base/macros.h"
+#include "ui/views/controls/native/native_view_host.h"
+
+namespace exo {
+class NotificationSurface;
+}
+
+namespace arc {
+
+class ArcCustomNotificationView : public views::NativeViewHost {
+ public:
+  explicit ArcCustomNotificationView(exo::NotificationSurface* surface);
+  ~ArcCustomNotificationView() override;
+
+ private:
+  // views::NativeViewHost
+  void ViewHierarchyChanged(
+      const ViewHierarchyChangedDetails& details) override;
+
+  exo::NotificationSurface* surface_;
+
+  DISALLOW_COPY_AND_ASSIGN(ArcCustomNotificationView);
+};
+
+}  // namespace arc
+
+#endif  // UI_ARC_NOTIFICATION_ARC_CUSTOM_NOTIFICATION_VIEW_H_