Mus Demo: Demonstrate external window mode

services/ui/demo/window_tree_data.cc

Index: services/ui/demo/window_tree_data.cc
diff --git a/services/ui/demo/window_tree_data.cc b/services/ui/demo/window_tree_data.cc
index 3d78c94df668343d7eb38d73ca32305ff5fd923c..9810b9fddc36a112d1a3ff3d2cefa5428625e5bd 100644
--- a/services/ui/demo/window_tree_data.cc
+++ b/services/ui/demo/window_tree_data.cc
@@ -59,6 +59,13 @@ void DrawSquare(const gfx::Rect& bounds,
 
 WindowTreeData::WindowTreeData(int square_size) : square_size_(square_size) {}
 
+WindowTreeData::WindowTreeData(mojom::WindowTreeHostFactory* factory,
+                               mojom::WindowTreeClientPtr tree_client,
+                               int square_size)
+    : square_size_(square_size) {
+  factory->CreateWindowTreeHost(MakeRequest(&host_), std::move(tree_client));
+}
+
 WindowTreeData::~WindowTreeData() {}
 
 aura::Window* WindowTreeData::bitmap_window() {