The random tree at depth 7 measured against the two revisions before it: the
GPU pass is a tenth of a millisecond everywhere, and every difference is the
CPU laying out. A repaint of one leaf costs 1313 draws and 6.5 ms where the
pre-#16 code cost one draw, because `redraw` escalates to the top size reader
before knowing whether the size changed at all. Drawing first and escalating
only on a different size takes that to one draw and takes a resize below the
pre-#16 number, but misplaces four widgets in the resize case, so it is the
owner's to call.
Also records the measure-by-drawing multiplier -- 1.3x the drawn widgets at
depth 4, 5.2x at depth 8 -- and that scrolling is now part of the random
trees.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>