arc: Show custom notification via notification surface

ui/arc/notification/arc_custom_notification_view.cc

Index: ui/arc/notification/arc_custom_notification_view.cc
diff --git a/ui/arc/notification/arc_custom_notification_view.cc b/ui/arc/notification/arc_custom_notification_view.cc
new file mode 100644
index 0000000000000000000000000000000000000000..a054ae18e960b2cc5500f9e91293853367335519
--- /dev/null
+++ b/ui/arc/notification/arc_custom_notification_view.cc
@@ -0,0 +1,38 @@
+// 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.
+
+#include "ui/arc/notification/arc_custom_notification_view.h"
+
+#include "components/exo/notification_surface.h"
+#include "components/exo/surface.h"
+#include "ui/views/widget/widget.h"
+
+namespace arc {
+
+ArcCustomNotificationView::ArcCustomNotificationView(
+    exo::NotificationSurface* surface)
+    : surface_(surface) {}
+
+ArcCustomNotificationView::~ArcCustomNotificationView() {}
+
+void ArcCustomNotificationView::ViewHierarchyChanged(
+    const views::View::ViewHierarchyChangedDetails& details) {
+  views::Widget* widget = GetWidget();
+
+  // Bail if native_view() has attached to a different widget.
+  if (widget && native_view() &&
+      views::Widget::GetTopLevelWidgetForNativeView(native_view()) != widget) {
+    return;
+  }
+
+  views::NativeViewHost::ViewHierarchyChanged(details);
+
+  if (!widget || !details.is_add)
+    return;
+
+  SetPreferredSize(surface_->GetSize());
+  Attach(surface_->surface()->window());
+}
+
+}  // namespace arc