Adds WindowManagerManager to mus

mash/wm/window_manager_application.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "mash/wm/window_manager_application.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "components/mus/public/cpp/event_matcher.h"
@@ skipping 98 matching lines @@
                                           uint32_t user_id) {
   connector_ = connector;
   tracing_.Initialize(connector, url);
 
   mus::mojom::WindowManagerFactoryServicePtr wm_factory_service;
   connector_->ConnectToInterface("mojo:mus", &wm_factory_service);
   wm_factory_service->SetWindowManagerFactory(
       window_manager_factory_binding_.CreateInterfacePtrAndBind());
 
   user_window_controller_.reset(new UserWindowControllerImpl());
-
-  root_controllers_.insert(
-      RootWindowController::CreateUsingWindowTreeHost(this));
 }
 
 bool WindowManagerApplication::AcceptConnection(mojo::Connection* connection) {
   connection->AddInterface<mash::wm::mojom::UserWindowController>(this);
   connection->AddInterface<mus::mojom::AcceleratorRegistrar>(this);
   if (connection->GetRemoteApplicationName() == "mojo:mash_shell")
     connection->GetInterface(&mash_shell_);
   return true;
 }
 
@@ skipping 30 matching lines @@
 
 void WindowManagerApplication::CreateWindowManager(
     mus::mojom::DisplayPtr display,
     mojo::InterfaceRequest<mus::mojom::WindowTreeClient> client_request) {
   root_controllers_.insert(RootWindowController::CreateFromDisplay(
       this, std::move(display), std::move(client_request)));
 }
 
 }  // namespace wm
 }  // namespace mash