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

ash/mus/window_manager_unittest.cc

Index: ash/mus/window_manager_unittest.cc
diff --git a/ash/mus/window_manager_unittest.cc b/ash/mus/window_manager_unittest.cc
index 168bb4b702fb215d3163cd0f267df51e08f28a84..d83211e0c28d1fae9878724b5fd413ad1554904a 100644
--- a/ash/mus/window_manager_unittest.cc
+++ b/ash/mus/window_manager_unittest.cc
@@ -90,7 +90,7 @@ TEST_F(WindowManagerTest, OpenWindow) {
 
   // Connect to mus and create a new top level window. The request goes to
   // |ash|, but is async.
-  aura::WindowTreeClient client(connector(), &window_tree_delegate);
+  aura::WindowTreeClient client(connector(), nullptr, &window_tree_delegate);
   client.ConnectViaWindowTreeFactory();
   aura::test::EnvTestHelper().SetWindowTreeClient(&client);
   std::map<std::string, std::vector<uint8_t>> properties;
@@ -108,8 +108,9 @@ TEST_F(WindowManagerTest, OpenWindow) {
   ui::mojom::WindowTreeClientPtr tree_client;
   auto tree_client_request = MakeRequest(&tree_client);
   client.Embed(child_window, std::move(tree_client), 0u, base::Bind(&OnEmbed));
-  aura::WindowTreeClient child_client(connector(), &window_tree_delegate,
-                                      nullptr, std::move(tree_client_request));
+  aura::WindowTreeClient child_client(connector(), nullptr,
+                                      &window_tree_delegate, nullptr,
+                                      std::move(tree_client_request));
   window_tree_delegate.WaitForEmbed();
   ASSERT_TRUE(!child_client.GetRoots().empty());
   window_tree_delegate.DestroyWindowTreeHost();