-webkit-margin-collpase is a non-standard extension added in https://trac.webkit.org/changeset/7362/webkit. I wonder if we can remove it.
There's a mention here:
Chrome usage counting:
This probably over-counts, according to Ian K.
*** Bug 204956 has been marked as a duplicate of this bug. ***
Just for future reference, this is the comment from ikilpatrick@ on the duplicated bug:
Blink is going to attempt to remove this in the M81 release, see:
Created attachment 447936 [details]
Created attachment 447939 [details]
Created attachment 447943 [details]
Comment on attachment 447943 [details]
View in context: https://bugs.webkit.org/attachment.cgi?id=447943&action=review
> + Rqa"Â§emove non-standard -webkit-margin-collapse CSS property and longhands
nit: fix commit message here
Created attachment 447944 [details]
Committed r287429 (245564@trunk): <https://commits.webkit.org/245564@trunk>