Revert of Splitting of layers for correct intersections

cc/trees/layer_tree_impl_unittest.cc

Index: cc/trees/layer_tree_impl_unittest.cc
diff --git a/cc/trees/layer_tree_impl_unittest.cc b/cc/trees/layer_tree_impl_unittest.cc
index 06df3c2f51493a0d31c73139555f5bc18cde5393..67f98e65a4ebef0dde18a93d37bd2e637be387ce 100644
--- a/cc/trees/layer_tree_impl_unittest.cc
+++ b/cc/trees/layer_tree_impl_unittest.cc
@@ -919,6 +919,14 @@
   ASSERT_TRUE(child2);
   ASSERT_TRUE(grand_child1);
   ASSERT_EQ(1u, RenderSurfaceLayerList().size());
+
+  RenderSurfaceImpl* root_render_surface =
+      host_impl().active_tree()->root_layer()->render_surface();
+  ASSERT_EQ(4u, root_render_surface->layer_list().size());
+  ASSERT_EQ(3, root_render_surface->layer_list().at(0)->id());
+  ASSERT_EQ(1, root_render_surface->layer_list().at(1)->id());
+  ASSERT_EQ(2, root_render_surface->layer_list().at(2)->id());
+  ASSERT_EQ(4, root_render_surface->layer_list().at(3)->id());
 
   // Nothing overlaps the root_layer at (1, 1), so hit testing there should find
   // the root layer.