cc : Remove parent for mask and replica layers in LayerImpl

cc/layers/layer_impl.cc

Index: cc/layers/layer_impl.cc
diff --git a/cc/layers/layer_impl.cc b/cc/layers/layer_impl.cc
index bcbec39c4b8cfabad04d0dfd3002c6c6ce3f305b..936a6d6645ff09f50a8c8fb9aa4404810f08ecb4 100644
--- a/cc/layers/layer_impl.cc
+++ b/cc/layers/layer_impl.cc
@@ -990,8 +990,6 @@ void LayerImpl::SetMaskLayer(scoped_ptr<LayerImpl> mask_layer) {
     layer_tree_impl_->AddLayer(std::move(mask_layer));
 
   mask_layer_id_ = new_layer_id;
-  if (mask_layer_)
-    mask_layer_->SetParent(this);
 }
 
 scoped_ptr<LayerImpl> LayerImpl::TakeMaskLayer() {
@@ -1020,8 +1018,6 @@ void LayerImpl::SetReplicaLayer(scoped_ptr<LayerImpl> replica_layer) {
     layer_tree_impl_->AddLayer(std::move(replica_layer));
 
   replica_layer_id_ = new_layer_id;
-  if (replica_layer_)
-    replica_layer_->SetParent(this);
 }
 
 scoped_ptr<LayerImpl> LayerImpl::TakeReplicaLayer() {