Add unittests of ArcCustomNotificationView

ui/arc/notification/arc_notification_surface_impl.cc

+// 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.
+
+#include "ui/arc/notification/arc_notification_surface_impl.h"
+
+#include "base/logging.h"
+#include "components/exo/notification_surface.h"
+#include "ui/views/controls/native/native_view_host.h"
+
+namespace arc {
+
+// Handles notification surface role of a given surface.
+ArcNotificationSurfaceImpl::ArcNotificationSurfaceImpl(
+    exo::NotificationSurface* surface)
+    : surface_(surface) {
+  DCHECK(surface);
+}
+
+gfx::Size ArcNotificationSurfaceImpl::GetSize() const {
+  return surface_->GetSize();
+}
+
+void ArcNotificationSurfaceImpl::AttachWindow(
+    views::NativeViewHost* native_view_host) {
+  return native_view_host->Attach(surface_->window());
+}
+
+aura::Window* ArcNotificationSurfaceImpl::GetWindow() const {
+  return surface_->window();
+}
+
+const std::string& ArcNotificationSurfaceImpl::GetNotificationId() const {
+  return surface_->notification_id();
+}
+
+}  // namespace arc