Chrome Version       : 54.0.2840.99 beta Windows
URLs (if applicable) :https://jsfiddle.net/Ly68eq8w/4/
Other browsers tested:
  Add OK or FAIL, along with the version, after other browsers where you
have tested this issue:
     Safari:
    Firefox:OK 49.0 Windows
         IE:

What steps will reproduce the problem?
An element [A] ...
... whose position is sticky
... whose container is body
... whose z-index is greater than 0
... which contains an element [B] ...
    ... whose position is absolute
    ... whose top is negative
An element [C] on the page that is animated or has 3d transformations applied. The following all trigger the problem: matrix3d, translate3d, translateZ, scale3d, scaleZ, rotate3d, rotateX, rotateY, perspective

What is the expected result?
[A] should stick to the top of the window with no gap when the page is scrolled.

What happens instead?
[A] is pushed down vertically on the page equal to the "top" amount declared on [B]

Please provide any additional information below. Attach a screenshot if
possible.

https://jsfiddle.net/Ly68eq8w/4/