chromium/third_party/blink/web_tests/compositing/background-color/background-color-outside-document.html

<!DOCTYPE html>
<script>

if (window.internals) {
    internals.settings.setViewportEnabled(true);
    internals.settings.setViewportMetaEnabled(true);
    addEventListener('load', function() {
        internals.setPageScaleFactorLimits(0.5, 4);
        internals.setPageScaleFactor(0.5);
    });
}

</script>
<meta name="viewport" content="width=device-width, minimum-scale=0.5, initial-scale=1, maximum-scale=1.25">
<style>
html {
    background-color: #8f8;
    height: 100%;
    border: 1px solid black;
}
body {
    background-color: #fcc;
}
#console {
    display: none;
}
</style>