<!DOCTYPE html>
<div style="height: 400px"></div>
<div style="height: 200px; width: 200px; transform: translateZ(0)">
<iframe srcdoc="<div style='height: 50px; width: 50px; background-color: green;'></div>"></iframe>
</div>
<!DOCTYPE html>
<div style="height: 400px"></div>
<div style="height: 200px; width: 200px; transform: translateZ(0)">
<iframe srcdoc="<div style='height: 50px; width: 50px; background-color: green;'></div>"></iframe>
</div>