Transfer LayerImpl ownership to LayerTreeImpl

cc/trees/layer_tree_host_common.cc

Index: cc/trees/layer_tree_host_common.cc
diff --git a/cc/trees/layer_tree_host_common.cc b/cc/trees/layer_tree_host_common.cc
index 83c9c7586f3f5ce2e4790fa9bba1b8f14de862c3..77b327b59b16814ecb6a4f7edc788ab83cb267f8 100644
--- a/cc/trees/layer_tree_host_common.cc
+++ b/cc/trees/layer_tree_host_common.cc
@@ -824,23 +824,23 @@ void CalculateRenderSurfaceLayerList(
   if (render_to_separate_surface)
     layer->render_surface()->SetAccumulatedContentRect(gfx::Rect());
 
-  for (const auto& child_layer : layer->children()) {
+  for (auto* child_layer : layer->children()) {
     CalculateRenderSurfaceLayerList(
-        child_layer.get(), property_trees, render_surface_layer_list,
-        descendants, nearest_occlusion_immune_ancestor, layer_is_drawn,
+        child_layer, property_trees, render_surface_layer_list, descendants,
+        nearest_occlusion_immune_ancestor, layer_is_drawn,
         can_render_to_separate_surface, current_render_surface_layer_list_id,
         max_texture_size);
 
     // If the child is its own render target, then it has a render surface.
-    if (child_layer->render_target() == child_layer.get() &&
+    if (child_layer->render_target() == child_layer &&
         !child_layer->render_surface()->layer_list().empty() &&
         !child_layer->render_surface()->content_rect().IsEmpty()) {
       // This child will contribute its render surface, which means
       // we need to mark just the mask layer (and replica mask layer)
       // with the id.
       MarkMasksWithRenderSurfaceLayerListId(
-          child_layer.get(), current_render_surface_layer_list_id);
-      descendants->push_back(child_layer.get());
+          child_layer, current_render_surface_layer_list_id);
+      descendants->push_back(child_layer);
     }
 
     if (child_layer->layer_or_descendant_is_drawn()) {