Revert of Splitting of layers for correct intersections

cc/trees/layer_tree_host_common_unittest.cc

Index: cc/trees/layer_tree_host_common_unittest.cc
diff --git a/cc/trees/layer_tree_host_common_unittest.cc b/cc/trees/layer_tree_host_common_unittest.cc
index 5d002d5cfb543b624716e1a73d4750b5319fc5ce..6f05035428a285c7fc1f13411b77b6a52f067b07 100644
--- a/cc/trees/layer_tree_host_common_unittest.cc
+++ b/cc/trees/layer_tree_host_common_unittest.cc
@@ -2975,6 +2975,78 @@
   EXPECT_FALSE(child->draw_properties().sorted_for_recursion);
 }
 
+TEST_F(LayerTreeHostCommonTest, WillSortAtContextBoundary) {
+  // Creates a layer tree that looks as follows:
+  // * root (sorting-context-id1)
+  //   * parent (sorting-context-id2)
+  //     * child1 (sorting-context-id2)
+  //     * child2 (sorting-context-id2)
+  //
+  // This test ensures that we sort at |parent| even though both it and root are
+  // set to be 3d sorted.
+  FakeImplProxy proxy;
+  TestSharedBitmapManager shared_bitmap_manager;
+  FakeLayerTreeHostImpl host_impl(&proxy, &shared_bitmap_manager);
+
+  scoped_ptr<LayerImpl> root_ptr(LayerImpl::Create(host_impl.active_tree(), 1));
+  LayerImpl* root = root_ptr.get();
+  scoped_ptr<LayerImpl> parent_ptr(
+      LayerImpl::Create(host_impl.active_tree(), 2));
+  LayerImpl* parent = parent_ptr.get();
+  scoped_ptr<LayerImpl> child1_ptr(
+      LayerImpl::Create(host_impl.active_tree(), 3));
+  LayerImpl* child1 = child1_ptr.get();
+  scoped_ptr<LayerImpl> child2_ptr(
+      LayerImpl::Create(host_impl.active_tree(), 4));
+  LayerImpl* child2 = child2_ptr.get();
+
+  gfx::Transform identity_matrix;
+  gfx::Transform below_matrix;
+  below_matrix.Translate3d(0.f, 0.f, -10.f);
+  gfx::Transform above_matrix;
+  above_matrix.Translate3d(0.f, 0.f, 10.f);
+
+  SetLayerPropertiesForTesting(root, identity_matrix, gfx::Point3F(),
+                               gfx::PointF(), gfx::Size(100, 100), true, true,
+                               true);
+  SetLayerPropertiesForTesting(parent, identity_matrix, gfx::Point3F(),
+                               gfx::PointF(), gfx::Size(50, 50), true, true,
+                               true);
+  SetLayerPropertiesForTesting(child1, above_matrix, gfx::Point3F(),
+                               gfx::PointF(), gfx::Size(50, 50), true, true,
+                               false);
+  SetLayerPropertiesForTesting(child2, below_matrix, gfx::Point3F(),
+                               gfx::PointF(), gfx::Size(50, 50), true, true,
+                               false);
+
+  root->Set3dSortingContextId(3);
+  root->SetDrawsContent(true);
+  parent->Set3dSortingContextId(7);
+  parent->SetDrawsContent(true);
+  child1->Set3dSortingContextId(7);
+  child1->SetDrawsContent(true);
+  child2->Set3dSortingContextId(7);
+  child2->SetDrawsContent(true);
+
+  parent->AddChild(child1_ptr.Pass());
+  parent->AddChild(child2_ptr.Pass());
+  root->AddChild(parent_ptr.Pass());
+
+  LayerImplList render_surface_layer_list;
+  LayerTreeHostCommon::CalcDrawPropsImplInputsForTesting inputs(
+      root_ptr.get(), root->bounds(), &render_surface_layer_list);
+  inputs.can_adjust_raster_scales = true;
+  LayerTreeHostCommon::CalculateDrawProperties(&inputs);
+
+  EXPECT_TRUE(root->render_surface());
+  EXPECT_EQ(2u, render_surface_layer_list.size());
+
+  EXPECT_EQ(3u, parent->render_surface()->layer_list().size());
+  EXPECT_EQ(child2->id(), parent->render_surface()->layer_list().at(0)->id());
+  EXPECT_EQ(parent->id(), parent->render_surface()->layer_list().at(1)->id());
+  EXPECT_EQ(child1->id(), parent->render_surface()->layer_list().at(2)->id());
+}
+
 TEST_F(LayerTreeHostCommonTest,
        SingularNonAnimatingTransformDoesNotPreventClearingDrawProperties) {
   scoped_refptr<Layer> root = Layer::Create();
@@ -7520,6 +7592,110 @@
   EXPECT_TRUE(render_surface_layer_list.at(2)->render_surface());
 }
 
+TEST_F(LayerTreeHostCommonTest, DoNotClobberSorting) {
+  // We rearrange layer list contributions if we have to visit children out of
+  // order, but it should be a 'stable' rearrangement. That is, the layer list
+  // additions for a single layer should not be reordered, though their position
+  // wrt to the contributions due to a sibling may vary.
+  //
+  // + root
+  //   + scroll_child
+  //     + top_content
+  //     + bottom_content
+  //   + scroll_parent_border
+  //     + scroll_parent_clip
+  //       + scroll_parent
+  //
+  FakeImplProxy proxy;
+  TestSharedBitmapManager shared_bitmap_manager;
+  FakeLayerTreeHostImpl host_impl(&proxy, &shared_bitmap_manager);
+  host_impl.CreatePendingTree();
+  scoped_ptr<LayerImpl> root = LayerImpl::Create(host_impl.active_tree(), 1);
+  scoped_ptr<LayerImpl> scroll_parent_border =
+      LayerImpl::Create(host_impl.active_tree(), 2);
+  scoped_ptr<LayerImpl> scroll_parent_clip =
+      LayerImpl::Create(host_impl.active_tree(), 3);
+  scoped_ptr<LayerImpl> scroll_parent =
+      LayerImpl::Create(host_impl.active_tree(), 4);
+  scoped_ptr<LayerImpl> scroll_child =
+      LayerImpl::Create(host_impl.active_tree(), 5);
+  scoped_ptr<LayerImpl> bottom_content =
+      LayerImpl::Create(host_impl.active_tree(), 6);
+  scoped_ptr<LayerImpl> top_content =
+      LayerImpl::Create(host_impl.active_tree(), 7);
+
+  scroll_parent_clip->SetMasksToBounds(true);
+
+  scroll_child->SetScrollParent(scroll_parent.get());
+  scoped_ptr<std::set<LayerImpl*>> scroll_children(new std::set<LayerImpl*>);
+  scroll_children->insert(scroll_child.get());
+  scroll_parent->SetScrollChildren(scroll_children.release());
+
+  scroll_child->SetDrawsContent(true);
+  scroll_parent->SetDrawsContent(true);
+  top_content->SetDrawsContent(true);
+  bottom_content->SetDrawsContent(true);
+
+  gfx::Transform identity_transform;
+  gfx::Transform top_transform;
+  top_transform.Translate3d(0.0, 0.0, 5.0);
+  gfx::Transform bottom_transform;
+  bottom_transform.Translate3d(0.0, 0.0, 3.0);
+
+  SetLayerPropertiesForTesting(root.get(), identity_transform, gfx::Point3F(),
+                               gfx::PointF(), gfx::Size(50, 50), true, false,
+                               true);
+  SetLayerPropertiesForTesting(scroll_parent_border.get(), identity_transform,
+                               gfx::Point3F(), gfx::PointF(), gfx::Size(40, 40),
+                               true, false, false);
+  SetLayerPropertiesForTesting(scroll_parent_clip.get(), identity_transform,
+                               gfx::Point3F(), gfx::PointF(), gfx::Size(30, 30),
+                               true, false, false);
+  SetLayerPropertiesForTesting(scroll_parent.get(), identity_transform,
+                               gfx::Point3F(), gfx::PointF(), gfx::Size(50, 50),
+                               true, false, false);
+  SetLayerPropertiesForTesting(scroll_child.get(), identity_transform,
+                               gfx::Point3F(), gfx::PointF(), gfx::Size(50, 50),
+                               true, false, false);
+  SetLayerPropertiesForTesting(top_content.get(), top_transform, gfx::Point3F(),
+                               gfx::PointF(), gfx::Size(50, 50), false, true,
+                               true);
+  SetLayerPropertiesForTesting(bottom_content.get(), bottom_transform,
+                               gfx::Point3F(), gfx::PointF(), gfx::Size(50, 50),
+                               false, true, true);
+
+  scroll_child->SetShouldFlattenTransform(false);
+  scroll_child->Set3dSortingContextId(1);
+
+  scroll_child->AddChild(top_content.Pass());
+  scroll_child->AddChild(bottom_content.Pass());
+  root->AddChild(scroll_child.Pass());
+
+  scroll_parent_clip->AddChild(scroll_parent.Pass());
+  scroll_parent_border->AddChild(scroll_parent_clip.Pass());
+  root->AddChild(scroll_parent_border.Pass());
+
+  LayerImplList render_surface_layer_list;
+  LayerTreeHostCommon::CalcDrawPropsImplInputsForTesting inputs(
+      root.get(), root->bounds(), &render_surface_layer_list);
+
+  LayerTreeHostCommon::CalculateDrawProperties(&inputs);
+
+  EXPECT_TRUE(root->render_surface());
+
+  // If we don't sort by depth and let the layers get added in the order they
+  // would normally be visited in, then layers 6 and 7 will be out of order. In
+  // other words, although we've had to shift 5, 6, and 7 to appear before 4
+  // in the list (because of the scroll parent relationship), this should not
+  // have an effect on the the order of 5, 6, and 7 (which had been reordered
+  // due to layer sorting).
+  EXPECT_EQ(4u, root->render_surface()->layer_list().size());
+  EXPECT_EQ(5, root->render_surface()->layer_list().at(0)->id());
+  EXPECT_EQ(6, root->render_surface()->layer_list().at(1)->id());
+  EXPECT_EQ(7, root->render_surface()->layer_list().at(2)->id());
+  EXPECT_EQ(4, root->render_surface()->layer_list().at(3)->id());
+}
+
 TEST_F(LayerTreeHostCommonTest, ScrollCompensationWithRounding) {
   // This test verifies that a scrolling layer that gets snapped to
   // integer coordinates doesn't move a fixed position child.