static void register_test_drawables(SkReadBuffer& buffer) {
    buffer.setCustomFactory(SkString("IntDrawable"), IntDrawable::CreateProc);
    buffer.setCustomFactory(SkString("PaintDrawable"), PaintDrawable::CreateProc);
    buffer.setCustomFactory(SkString("CompoundDrawable"), CompoundDrawable::CreateProc);
    buffer.setCustomFactory(SkString("RootDrawable"), RootDrawable::CreateProc);
}