Chrome Version: 58.0.2994.0
OS: All

What steps will reproduce the problem?
(1) Visit http://output.jsbin.com/woqicun
(2) Scroll the body.

What is the expected result?
Technically, both of the blue sticky boxes should stick 50px below the top of the viewport.

What happens instead?
Instead, the sticky box on the right (as it is a descendant of the overflow scroller) tries to stick 50px below the top of that scroller.

Interestingly, Firefox does not handle this case at all and both sticky boxes just don't stick. We could easily reproduce this behavior by nulling out the ancestorOverflowLayer whenever we pass a fixed position element as we propagate it down the PaintLayer tree, making it impossible to store the sticky position constraints.

Alternately, since fixed position doesn't move during the scroll of the page we could probably calculate the correct sticky position during layout and not try to update the sticky position during scroll / compositing.

Please use labels and text to provide additional information.

For graphics-related bugs, please copy/paste the contents of the about:gpu
page at the end of this report.