jfernandez@ can you have a look? Apologies if I'm totally off.

After running "git revert a90dba1f2dd094e51229dd2e5e059c6b53cee93a" on my Canary build, both pages layout correctly.

 Issue 699568  has been merged into this issue.

Related bug explains more clearly what is going on here ("Elements with display: flex and ::before display: row render content outside content box") and it includes a reduced test case.

Example URL:
http://codepen.io/tcschiller/pen/Qpdbjo

Steps to reproduce the problem:
The above codepen shows the issue. If flex on the element itself or table on the ::before element is removed, content renders correctly.

I haven't look at the issue in detail, but it may be related to my change, indeed.  

In fact, I'm investigating  issue #699116  as well, probably caused by the mentioned patch. 

Perhaps it'd be a good idea to revert it, so I can investigate both issues more carefully. 

https://crrev.com/2528253003 has been reverted. Could anybody verify the regression is solved now ?

After syncing to the latest (f78878b8ba3) and rebuilding Chromium, this is now fixed (verified on Twitter, Apple docs, and the codepen repro)

It might be a good idea to land a layout test for this, since it's pretty amazing that we didn't catch this in the CQ for the original change.

In any case, I think we should merge https://crrev.com/2740063003 in M59 as soon as possible.

Sorry about the confusion, no need to merge.

I'll mark this issue as FIXED then.
Thanks for verifying it.

I'll try to define a layout test for this issue as part of the proper fix of issue 667785, which patch has been the responsible of several regressions. I'll try also t define layout test cases based on them.