mus: Changes SetDisplayRoot() to create actual display

services/ui/display/screen_manager_forwarding.cc

 // Copyright 2017 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/display/screen_manager_forwarding.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "services/service_manager/public/cpp/binder_registry.h"
@@ skipping 17 matching lines @@
         mode->refresh_rate() == mode_to_find->refresh_rate()) {
       return mode.get();
     }
   }
   NOTREACHED();
   return nullptr;
 }
 
 }  // namespace
 
-// TODO(sky/kylechar): Change ScreenManager::Create() to make a
-// ScreenManagerForwarding in mus mode.
-
 ScreenManagerForwarding::ScreenManagerForwarding() : binding_(this) {}
 
 ScreenManagerForwarding::~ScreenManagerForwarding() {
   if (native_display_delegate_)
     native_display_delegate_->RemoveObserver(this);
 }
 
 void ScreenManagerForwarding::AddInterfaces(
     service_manager::BinderRegistry* registry) {
   registry->AddInterface<mojom::NativeDisplayDelegate>(this);
@@ skipping 140 matching lines @@
   if (status) {
     // Modify display snapshot similar to how ConfigureDisplaysTask would. Ozone
     // DRM needs these to be changed and ConfigureDisplaysTasks can't do it.
     snapshot->set_current_mode(mode);
     snapshot->set_origin(origin);
   }
   callback.Run(status);
 }
 
 }  // namespace display