Mus Demo: Demonstrate external window mode

services/ui/demo/mus_demo_unittests.cc

Index: services/ui/demo/mus_demo_unittests.cc
diff --git a/services/ui/demo/mus_demo_unittests.cc b/services/ui/demo/mus_demo_unittests.cc
index 661536718a332c3d363c774d3e1a6dfe3a990fcb..d3c2a42e95ce49aeae8c7b2db6031d873eb0d22d 100644
--- a/services/ui/demo/mus_demo_unittests.cc
+++ b/services/ui/demo/mus_demo_unittests.cc
@@ -39,7 +39,7 @@ class MusDemoTest : public service_manager::test::ServiceTest {
 
 }  // namespace
 
-TEST_F(MusDemoTest, CheckMusDemoDraws) {
+TEST_F(MusDemoTest, CheckMusDemoInternalDraws) {
   connector()->Connect("mus_demo_internal");
 
   ::ui::mojom::WindowServerTestPtr test_interface;
@@ -56,5 +56,22 @@ TEST_F(MusDemoTest, CheckMusDemoDraws) {
   EXPECT_TRUE(success);
 }
 
+TEST_F(MusDemoTest, CheckMusDemoExternalDraws) {
+  connector()->Connect("mus_demo_external");
+
+  ::ui::mojom::WindowServerTestPtr test_interface;
+  connector()->BindInterface(ui::mojom::kServiceName, &test_interface);
+
+  base::RunLoop run_loop;
+  bool success = false;
+  // TODO(kylechar): Fix WindowServer::CreateTreeForWindowManager so that the
+  // WindowTree has the correct name instead of an empty name.
+  test_interface->EnsureClientHasDrawnWindow(
+      "",  // WindowTree name is empty.
+      base::Bind(&RunCallback, &success, run_loop.QuitClosure()));
+  run_loop.Run();
+  EXPECT_TRUE(success);
+}
+
 }  // namespace demo
 }  // namespace ui