Brush art leaves out the symbol instances and pattern paints whose art
draws a brushed stroke. The brush cache now records whether a brush's art
or the stroke's paint can show a symbol or a pattern, and drops those
entries when the art of the document's symbols or patterns changes, so an
edit that makes a symbol or pattern start or stop drawing a brushed stroke
draws as a new renderer does.
The parity line gives the median and fastest-frame figures of the
benchmark for both documents it names.