mus: Changes SetDisplayRoot() to create actual display

services/ui/display/screen_manager_ozone_internal.h

 // Copyright 2016 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.
 
 #ifndef SERVICES_UI_DISPLAY_SCREEN_MANAGER_OZONE_INTERNAL_H_
 #define SERVICES_UI_DISPLAY_SCREEN_MANAGER_OZONE_INTERNAL_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 34 matching lines @@
  public:
   ScreenManagerOzoneInternal();
   ~ScreenManagerOzoneInternal() override;
 
   void SetPrimaryDisplayId(int64_t display_id);
 
   // ScreenManager:
   void AddInterfaces(service_manager::BinderRegistry* registry) override;
   void Init(ScreenManagerDelegate* delegate) override;
   void RequestCloseDisplay(int64_t display_id) override;
+  display::ScreenBase* GetScreen() override;
 
   // mojom::TestDisplayController:
   void ToggleAddRemoveDisplay() override;
   void ToggleDisplayResolution() override;
 
   // mojom::DisplayController:
   void IncreaseInternalDisplayZoom() override;
   void DecreaseInternalDisplayZoom() override;
   void ResetInternalDisplayZoom() override;
   void RotateCurrentDisplayCW() override;
@@ skipping 62 matching lines @@
 
   mojo::BindingSet<mojom::DisplayController> controller_bindings_;
   mojo::BindingSet<mojom::TestDisplayController> test_bindings_;
 
   DISALLOW_COPY_AND_ASSIGN(ScreenManagerOzoneInternal);
 };
 
 }  // namespace display
 
 #endif  // SERVICES_UI_DISPLAY_SCREEN_MANAGER_OZONE_INTERNAL_H_