Google Chrome	57.0.2987.146 (Official Build) (64-bit)
Revision	0
Platform	9202.64.0 (Official Build) stable-channel samus

What steps will reproduce the problem?
(1) Load http://go/whogotp
(2) Scroll.

What is the expected result?

Should not checkerboard, the page is static with no script, just a hover effect that causes the bottom right corner of the page to change to show a hover card effect. Only the bottom corner tiles should repaint and re-record.

What happens instead?

Constant checkerboarding, massive repaints of the entire document, with main thread swamped in UpdateLayerTree calls taking 180ms on a Pixel 2, and each hit test taking 30ms. The layout and style combined seem to be about 30ms at the most. Also the rasterization takes 16-30ms.

Note that the document does have 75467 elements in it which is certainly "too many", but the Paint and UpdateLayerTree costs seem way off, since style, layout, hit test and rasterization are all <= 30ms, and UpdateLayerTree and Paint is 265ms or 9x slower per frame.