aura: Some change to how the client-lib is set up.

services/ui/demo/mus_demo.cc

Index: services/ui/demo/mus_demo.cc
diff --git a/services/ui/demo/mus_demo.cc b/services/ui/demo/mus_demo.cc
index a924a1d36f282157fccc5591c68d1d6d58a31002..042be52867b38ecdd2a033fcb2a4077c47f43b81 100644
--- a/services/ui/demo/mus_demo.cc
+++ b/services/ui/demo/mus_demo.cc
@@ -17,7 +17,6 @@
 #include "third_party/skia/include/core/SkRect.h"
 #include "ui/aura/client/default_capture_client.h"
 #include "ui/aura/env.h"
-#include "ui/aura/mus/mus_context_factory.h"
 #include "ui/aura/mus/property_converter.h"
 #include "ui/aura/mus/window_tree_client.h"
 #include "ui/aura/mus/window_tree_host_mus.h"
@@ -83,12 +82,8 @@ void MusDemo::OnStart() {
   property_converter_ = base::MakeUnique<aura::PropertyConverter>();
   wm_state_ = base::MakeUnique<::wm::WMState>();
 
-  gpu_ = Gpu::Create(context()->connector());
-  context_factory_ = base::MakeUnique<aura::MusContextFactory>(gpu_.get());
-  env_->set_context_factory(context_factory_.get());
-
   window_tree_client_ = base::MakeUnique<aura::WindowTreeClient>(
-      context()->connector(), this, this);
+      context()->connector(), nullptr /* io_task_runner */, this, this);
   window_tree_client_->ConnectAsWindowManager();
 
   env_->SetWindowTreeClient(window_tree_client_.get());