cc: Remove layers that are not drawn from tile manager.

cc/layers/picture_layer_impl.cc

Index: cc/layers/picture_layer_impl.cc
diff --git a/cc/layers/picture_layer_impl.cc b/cc/layers/picture_layer_impl.cc
index bd3b9dc590e413bf998aa6325f95d8fd36386239..2b9429470b93c05c3ba1a115c81ffd1f5630065c 100644
--- a/cc/layers/picture_layer_impl.cc
+++ b/cc/layers/picture_layer_impl.cc
@@ -354,10 +354,16 @@ void PictureLayerImpl::AppendQuads(QuadSink* quad_sink,
 }
 
 void PictureLayerImpl::DidUnregisterLayer() {
+  TRACE_EVENT0("cc", "PictureLayerImpl::DidUnregisterLayer");
+
   layer_needs_to_register_itself_ = true;
+  RemoveAllTilings();
 }
 
 void PictureLayerImpl::UpdateTilePriorities() {
+  TRACE_EVENT0("cc", "PictureLayerImpl::UpdateTilePriorities");
+
+  DCHECK(IsDrawnRenderSurfaceLayerListMember());
   DCHECK(!needs_post_commit_initialization_);
   CHECK(should_update_tile_priorities_);