wip: not for commit (update twin relationship)

cc/layers/picture_layer.cc

Index: cc/layers/picture_layer.cc
diff --git a/cc/layers/picture_layer.cc b/cc/layers/picture_layer.cc
index 8b8558ce7f4e59654cd85c257b19755ec04c469e..d7f8863a142b3838b9835e691819f5bd0d7eaef1 100644
--- a/cc/layers/picture_layer.cc
+++ b/cc/layers/picture_layer.cc
@@ -57,6 +57,9 @@ void PictureLayer::PushPropertiesTo(LayerImpl* base_layer) {
   layer_impl->invalidation_.Clear();
   layer_impl->invalidation_.Swap(&pile_invalidation_);
   layer_impl->pile_ = PicturePileImpl::CreateFromOther(pile_.get());
+
+  // Update the twin relationship as soon as possible.
+  layer_impl->UpdateTwinRelationship();
 }
 
 void PictureLayer::SetLayerTreeHost(LayerTreeHost* host) {