Generalize layer mirroring for phantom windows

content/browser/renderer_host/render_widget_host_view_aura_unittest.cc

 // Copyright (c) 2012 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 "content/browser/renderer_host/render_widget_host_view_aura.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <tuple>
@@ skipping 1870 matching lines @@
 
   EXPECT_CALL(observer, OnDelegatedFrameDamage(view_->window_,
                                                gfx::Rect(5, 5, 5, 5)));
   view_->OnSwapCompositorFrame(
       0, MakeDelegatedFrame(1.f, view_size, gfx::Rect(5, 5, 5, 5)));
   testing::Mock::VerifyAndClearExpectations(&observer);
 
   view_->window_->RemoveObserver(&observer);
 }
 
-// Recreating the layers for a window should cause Surface destruction to
+// Mirroring the layers for a window should cause Surface destruction to
 // depend on both layers.
-TEST_F(RenderWidgetHostViewAuraTest, RecreateLayers) {
+TEST_F(RenderWidgetHostViewAuraTest, MirrorLayers) {
   gfx::Size view_size(100, 100);
   gfx::Rect view_rect(view_size);
+  aura::Window* const root = parent_view_->GetNativeView()->GetRootWindow();
 
   view_->InitAsChild(nullptr);
   aura::client::ParentWindowWithContext(
-      view_->GetNativeView(), parent_view_->GetNativeView()->GetRootWindow(),
-      gfx::Rect());
+      view_->GetNativeView(), root, gfx::Rect());
   view_->SetSize(view_size);
   view_->Show();
 
   view_->OnSwapCompositorFrame(0,
                                MakeDelegatedFrame(1.f, view_size, view_rect));
-  std::unique_ptr<ui::LayerTreeOwner> cloned_owner(
-      wm::RecreateLayers(view_->GetNativeView(), nullptr));
+  std::unique_ptr<ui::LayerTreeOwner> mirror(
+      wm::MirrorLayers(view_->GetNativeView(), nullptr));
 
   cc::SurfaceId id = view_->GetDelegatedFrameHost()->SurfaceIdForTesting();
   if (!id.is_null()) {
     ImageTransportFactory* factory = ImageTransportFactory::GetInstance();
     cc::SurfaceManager* manager = factory->GetSurfaceManager();
     cc::Surface* surface = manager->GetSurfaceForId(id);
     EXPECT_TRUE(surface);
-    // Should be a SurfaceSequence for both the original and new layers.
+
+    // An orphaned mirror should not be a destruction dependency.
+    EXPECT_EQ(1u, surface->GetDestructionDependencyCount());
+
+    // Both layers should be destruction dependencies.
+    root->layer()->Add(mirror->root());
     EXPECT_EQ(2u, surface->GetDestructionDependencyCount());
+    root->layer()->Remove(mirror->root());
   }
 }
 
 // If the view size is larger than the compositor frame then extra layers
 // should be created to fill the gap.
 TEST_F(RenderWidgetHostViewAuraTest, DelegatedFrameGutter) {
   gfx::Size large_size(100, 100);
   gfx::Size small_size(40, 45);
   gfx::Size medium_size(40, 95);
 
@@ skipping 2751 matching lines @@
 
     // Retrieve the selected text from clipboard and verify it is as expected.
     base::string16 result_text;
     clipboard->ReadText(ui::CLIPBOARD_TYPE_SELECTION, &result_text);
     EXPECT_EQ(expected_text, result_text);
   }
 }
 #endif
 
 }  // namespace content