chromeos: Makes mushrome use simplified display management

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 19 matching lines @@
       return mode.get();
     }
   }
   NOTREACHED();
   return nullptr;
 }
 
 }  // namespace
 
 ScreenManagerForwarding::ScreenManagerForwarding()
-    : screen_(base::MakeUnique<display::ScreenBase>()), binding_(this) {}
+    : screen_(base::MakeUnique<display::ScreenBase>()), binding_(this) {
+  Screen::SetScreenInstance(screen_.get());
+}
 
 ScreenManagerForwarding::~ScreenManagerForwarding() {
   if (native_display_delegate_)
     native_display_delegate_->RemoveObserver(this);
+  Screen::SetScreenInstance(nullptr);
 }
 
 void ScreenManagerForwarding::AddInterfaces(
     service_manager::BinderRegistry* registry) {
   registry->AddInterface<mojom::NativeDisplayDelegate>(this);
 }
 
 void ScreenManagerForwarding::Init(ScreenManagerDelegate* delegate) {
   // Done in NativeDisplayDelegate::Initialize() instead.
 }
@@ skipping 150 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