Adds ability for WindowManager to create display roots

services/ui/ws/window_server.cc

 // Copyright 2014 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 "services/ui/ws/window_server.h"
 
 #include <set>
 #include <string>
 
 #include "base/logging.h"
@@ skipping 115 matching lines @@
                            mojom::WindowTreePtr tree_ptr) {
   CHECK_EQ(0u, tree_map_.count(tree_impl_ptr->id()));
   WindowTree* tree = tree_impl_ptr.get();
   tree_map_[tree->id()] = std::move(tree_impl_ptr);
   tree->Init(std::move(binding), std::move(tree_ptr));
 }
 
 WindowTree* WindowServer::CreateTreeForWindowManager(
     const UserId& user_id,
     mojom::WindowTreeRequest window_tree_request,
-    mojom::WindowTreeClientPtr window_tree_client) {
+    mojom::WindowTreeClientPtr window_tree_client,
+    bool automatically_create_display_roots) {
   std::unique_ptr<WindowTree> window_tree(new WindowTree(
       this, user_id, nullptr, base::WrapUnique(new WindowManagerAccessPolicy)));
   std::unique_ptr<WindowTreeBinding> window_tree_binding =
       delegate_->CreateWindowTreeBinding(
           WindowServerDelegate::BindingType::WINDOW_MANAGER, this,
           window_tree.get(), &window_tree_request, &window_tree_client);
   if (!window_tree_binding) {
     window_tree_binding = base::MakeUnique<DefaultWindowTreeBinding>(
         window_tree.get(), this, std::move(window_tree_request),
         std::move(window_tree_client));
   }
   WindowTree* window_tree_ptr = window_tree.get();
   AddTree(std::move(window_tree), std::move(window_tree_binding), nullptr);
-  window_tree_ptr->ConfigureWindowManager();
+  window_tree_ptr->ConfigureWindowManager(automatically_create_display_roots);
   return window_tree_ptr;
 }
 
 void WindowServer::DestroyTree(WindowTree* tree) {
   std::unique_ptr<WindowTree> tree_ptr;
   {
     auto iter = tree_map_.find(tree->id());
     DCHECK(iter != tree_map_.end());
     tree_ptr = std::move(iter->second);
     tree_map_.erase(iter);
@@ skipping 695 matching lines @@
 void WindowServer::OnUserIdAdded(const UserId& id) {
   activity_monitor_map_[id] = base::MakeUnique<UserActivityMonitor>(nullptr);
 }
 
 void WindowServer::OnUserIdRemoved(const UserId& id) {
   activity_monitor_map_.erase(id);
 }
 
 }  // namespace ws
 }  // namespace ui