This text should be autosized to 20px computed font size (16 * 400/320), since the position:absolute causes this to be a new cluster.

This text should be autosized to 21px computed font size (16 * 420/320), since the float:left causes this to be a new cluster.

This text should be autosized to 22px computed font size (16 * 440/320), since the perpendicular writing-mode compared to its containing block causes this to be a new cluster. Unfortunately due to http://webkit.org/b/96557 the height:440px is incorrectly interpreted as constraining the logicalHeight, so it doesn't get autosized.