Generalize layer mirroring for phantom windows

ash/rotator/screen_rotation_animator.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 "ash/rotator/screen_rotation_animator.h"
 
 #include <string>
 #include <utility>
 #include <vector>
 
@@ skipping 151 matching lines @@
 
   const int old_layer_initial_rotation_degrees =
       (Is180DegreeFlip(initial_orientation, new_rotation) ? 180 : 90);
 
   const base::TimeDelta duration =
       base::TimeDelta::FromMilliseconds(kRotationDurationInMs);
 
   const gfx::Tween::Type tween_type = gfx::Tween::FAST_OUT_LINEAR_IN;
 
   std::unique_ptr<ui::LayerTreeOwner> old_layer_tree =
-      ::wm::RecreateLayers(root_window, nullptr);
+      ::wm::RecreateLayers(root_window);
 
   // Add the cloned layer tree in to the root, so it will be rendered.
   root_window->layer()->Add(old_layer_tree->root());
   root_window->layer()->StackAtTop(old_layer_tree->root());
 
   std::unique_ptr<LayerCleanupObserver> layer_cleanup_observer(
       new LayerCleanupObserver(std::move(old_layer_tree)));
 
   Shell::GetInstance()->display_manager()->SetDisplayRotation(
       display_id, new_rotation, source);
@@ skipping 77 matching lines @@
   const display::Display::Rotation current_rotation =
       GetCurrentRotation(display_id_);
 
   if (current_rotation == new_rotation)
     return;
 
   RotateScreen(display_id_, new_rotation, source);
 }
 
 }  // namespace ash