While computing visual overflow rect we call enclosingLayoutRect() (floored position and ceiled size) which may produce different result for subpixel on. failed cases: fast/css/text-overflow-ellipsis-bidi.html fast/css/text-overflow-ellipsis-strict.html fast/css/text-overflow-ellipsis.html fast/css/text-overflow-input.html
Probably OK behavior.
Can we mark this as done?