Generalize layer mirroring for phantom windows

ui/views/view_unittest_aura.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 "ui/views/view.h"
 
 #include <memory>
 
 #include "ui/aura/window.h"
 #include "ui/compositor/layer.h"
@@ skipping 104 matching lines @@
   // Verify the value of Widget::GetRootLayers(). It should only include layers
   // from layer-backed Views descended from the Widget's root View.
   std::vector<ui::Layer*> old_w1_root_sublayers = w1->GetRootLayers();
   ASSERT_EQ(3u, old_w1_root_sublayers.size());
   EXPECT_EQ(v1_layer, old_w1_root_sublayers[0]);
   EXPECT_EQ(v4_layer, old_w1_root_sublayers[1]);
   EXPECT_EQ(v7_layer, old_w1_root_sublayers[2]);
 
   {
     std::unique_ptr<ui::LayerTreeOwner> cloned_owner(
-        wm::RecreateLayers(w1->GetNativeView(), nullptr));
+        wm::RecreateLayers(w1->GetNativeView()));
     EXPECT_EQ(w1_layer, cloned_owner->root());
     EXPECT_NE(w1_layer, w1->GetNativeView()->layer());
 
     // The old layers should still exist and have the same hierarchy.
     ASSERT_EQ("w1", w1_layer->name());
     ASSERT_EQ("v1 v4 w2 v7", ui::test::ChildLayerNamesAsString(*w1_layer));
     ASSERT_EQ("v5", ui::test::ChildLayerNamesAsString(*w2_layer));
     ASSERT_EQ("v6", ui::test::ChildLayerNamesAsString(*v5_layer));
     EXPECT_EQ("v8 v9", ui::test::ChildLayerNamesAsString(*v7_layer));
 
@@ skipping 37 matching lines @@
     std::vector<ui::Layer*> new_w1_root_sublayers = w1->GetRootLayers();
     ASSERT_EQ(3u, new_w1_root_sublayers.size());
     EXPECT_EQ(v1_new_layer, new_w1_root_sublayers[0]);
     EXPECT_EQ(v4_new_layer, new_w1_root_sublayers[1]);
     EXPECT_EQ(v7_new_layer, new_w1_root_sublayers[2]);
   }
   w1->CloseNow();
 }
 
 }  // namespace views