cc : Layers with singular transforms and copy request should be drawn

cc/trees/layer_tree_host_common_unittest.cc

 // Copyright 2011 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 "cc/trees/layer_tree_host_common.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 #include <memory>
@@ skipping 5631 matching lines @@
   // We should have two render surface, as the others are clipped out.
   ASSERT_EQ(2u, render_surface_list.size());
   EXPECT_EQ(root_layer->id(), render_surface_list.at(0)->id());
 
   // The root render surface should have only 2 contributing layer, since the
   // other layers are clipped away.
   ASSERT_EQ(2, root_layer->GetRenderSurface()->num_contributors());
   EXPECT_TRUE(root_layer->contributes_to_drawn_render_surface());
 }
 
+TEST_F(LayerTreeHostCommonTest, SingularTransformAndCopyRequests) {
+  LayerImpl* root = root_layer_for_testing();
+  root->SetBounds(gfx::Size(50, 50));
+  root->SetDrawsContent(true);
+
+  LayerImpl* singular_transform_layer = AddChild<LayerImpl>(root);
+  singular_transform_layer->SetBounds(gfx::Size(100, 100));
+  singular_transform_layer->SetDrawsContent(true);
+  gfx::Transform singular;
+  singular.Scale3d(6.f, 6.f, 0.f);
+  singular_transform_layer->test_properties()->transform = singular;
+
+  LayerImpl* copy_layer = AddChild<LayerImpl>(singular_transform_layer);
+  copy_layer->SetBounds(gfx::Size(100, 100));
+  copy_layer->SetDrawsContent(true);
+  copy_layer->test_properties()->copy_requests.push_back(
+      CopyOutputRequest::CreateRequest(base::Bind(&EmptyCopyOutputCallback)));
+
+  LayerImpl* copy_child = AddChild<LayerImpl>(copy_layer);
+  copy_child->SetBounds(gfx::Size(100, 100));
+  copy_child->SetDrawsContent(true);
+
+  LayerImpl* copy_grand_child = AddChild<LayerImpl>(copy_child);
+  copy_grand_child->SetBounds(gfx::Size(100, 100));
+  copy_grand_child->SetDrawsContent(true);
+  copy_grand_child->test_properties()->transform = singular;
+
+  DCHECK(!copy_layer->test_properties()->copy_requests.empty());
+  ExecuteCalculateDrawProperties(root);
+  DCHECK(copy_layer->test_properties()->copy_requests.empty());
+
+  // A layer with singular transform should not contribute to drawn render
+  // surface.
+  EXPECT_FALSE(singular_transform_layer->contributes_to_drawn_render_surface());
+  // Even though copy_layer and copy_child have singular screen space transform,
+  // they still contribute to drawn render surface as their transform to the
+  // closest ancestor with copy request is not singular.
+  EXPECT_TRUE(copy_layer->contributes_to_drawn_render_surface());
+  EXPECT_TRUE(copy_child->contributes_to_drawn_render_surface());
+  // copy_grand_child's transform to its closest ancestor with copy request is
+  // also singular. So, it doesn't contribute to drawn render surface.
+  EXPECT_FALSE(copy_grand_child->contributes_to_drawn_render_surface());
+}
+
 TEST_F(LayerTreeHostCommonTest, VisibleRectInNonRootCopyRequest) {
   LayerImpl* root = root_layer_for_testing();
   root->SetBounds(gfx::Size(50, 50));
   root->SetDrawsContent(true);
   root->SetMasksToBounds(true);
 
   LayerImpl* copy_layer = AddChild<LayerImpl>(root);
   copy_layer->SetBounds(gfx::Size(100, 100));
   copy_layer->SetDrawsContent(true);
   copy_layer->test_properties()->force_render_surface = true;
@@ skipping 5211 matching lines @@
 
   // Check child layer draw properties.
   EXPECT_EQ(gfx::Rect(10, 10), child->visible_layer_rect());
   EXPECT_EQ(gfx::Transform(), child->DrawTransform());
   EXPECT_EQ(gfx::Rect(10, 10), child->clip_rect());
   EXPECT_EQ(gfx::Rect(10, 10), child->drawable_content_rect());
 }
 
 }  // namespace
 }  // namespace cc