<!DOCTYPE html>
<style>
#layer {
    transform: translateZ(0);
    width: 20px;
    height: 20px;
}
</style>
<div id="layer"></div>
<iframe srcdoc="<div style='width: 15px;'></div>"></iframe>
<script>
    onload = function() {
        if (window.testRunner) {
            testRunner.dumpAsText();
            var output = "Verify we get the default scroll-blocks-on mode applied to the viewport, no additional layers created (even with an iframe), and no scroll-blocks-on mode applied to any other layer.\n\n";
            output += internals.layerTreeAsText(document, internals.LAYER_TREE_INCLUDES_SCROLL_BLOCKS_ON);
            testRunner.setCustomTextOutput(output);
        }
    };
</script>