Eliminate WindowTreeConnection

components/mus/demo/mus_demo.h

Index: components/mus/demo/mus_demo.h
diff --git a/components/mus/demo/mus_demo.h b/components/mus/demo/mus_demo.h
index 4632a951f196a2e387bb3bf4803cae29121bdebd..28c9de2e8736818ef6b1dd9b19b498986ded6be2 100644
--- a/components/mus/demo/mus_demo.h
+++ b/components/mus/demo/mus_demo.h
@@ -15,7 +15,7 @@
 #include "base/timer/timer.h"
 #include "components/mus/public/cpp/window.h"
 #include "components/mus/public/cpp/window_manager_delegate.h"
-#include "components/mus/public/cpp/window_tree_delegate.h"
+#include "components/mus/public/cpp/window_tree_client_delegate.h"
 #include "components/mus/public/interfaces/window_manager_factory.mojom.h"
 #include "mojo/public/cpp/bindings/binding_set.h"
 #include "services/shell/public/cpp/connector.h"
@@ -33,7 +33,7 @@ namespace mus_demo {
 // simple way to demonstrate that the graphic stack works as intended.
 class MusDemo : public shell::ShellClient,
                 public mus::mojom::WindowManagerFactory,
-                public mus::WindowTreeDelegate,
+                public mus::WindowTreeClientDelegate,
                 public mus::WindowManagerDelegate {
  public:
   MusDemo();
@@ -46,10 +46,10 @@ class MusDemo : public shell::ShellClient,
                   uint32_t id) override;
   bool AcceptConnection(shell::Connection* connection) override;
 
-  // WindowTreeDelegate:
+  // WindowTreeClientDelegate:
   void OnEmbed(mus::Window* root) override;
   void OnUnembed(mus::Window* root) override;
-  void OnConnectionLost(mus::WindowTreeConnection* connection) override;
+  void OnWindowTreeClientDestroyed(mus::WindowTreeClient* client) override;
   void OnEventObserved(const ui::Event& event, mus::Window* target) override;
 
   // mus::mojom::WindowManagerFactory:
@@ -79,7 +79,6 @@ class MusDemo : public shell::ShellClient,
   shell::Connector* connector_ = nullptr;
 
   mus::Window* window_ = nullptr;
-  std::unique_ptr<mus::WindowTreeConnection> window_tree_connection_;
   mus::WindowManagerClient* window_manager_client_ = nullptr;
   mojo::Binding<mus::mojom::WindowManagerFactory>
       window_manager_factory_binding_;