Moved issue monorail:3046 to now be issue chromium:763402.

Able to reproduce on 61.0.3142.0 with the mentioned steps on Ubuntu 14.04 and windows 7 and same thing is working fine on 61.0.3141.0

Issue is not reproducible on ODC Environment

Below is the Bisect Information:
=====================
Good build: 61.0.3141.0
Bad Build : 61.0.3142.0

You are probably looking for a change made after 473716 (known good), but no later than 473717 (first known bad).

changelog: https://chromium.googlesource.com/chromium/src/+log/1ade9dfba70113fb2e9898bb187248ed18d07a05..eb499bd02c68f68b5f74d534a673e920f8e7a5e6
From the above change log Suspecting: https://chromium-review.googlesource.com/525536

@ karlo - Could you please check whether this is caused with respect to your change, if not please help us in assigning it to the right owner.

Issue is repro on Mac OS 10.12.6,Windows-10, Linux Ubuntu 14.04 on the latest canary(63.0.3209.0) and stable(61.0.3163.79)

Please get this fixed before M62 hits stable.

Able to reproduce this issue on chrome latest canary #63.0.3218.0.

karlo@ Since this issue is marked as RB-Stable for M-62, could you please let us know is there any latest update available on this issue?

Thanks!

Confirm that I see the bug.  Will investigate.

This is not a bug.  The code previous to https://chromium-review.googlesource.com/c/chromium/src/+/525536 would always clamp values < 1.0px up to 1.0px, ie. the 0.5px border value in the test case above would essentially be ignored, and a value of 1px used instead.

The reason that the borders disappear is that the inner box paints over the border.  Eg. when the outer box is 0.5px border + 100px + 0.5px border = 101px, and the inner box is 100px, one side border of the outer box will be painted over.  

A solution in this case would be to not set a background on the inner element or not use .5px borders.

Additionally, the blink paint layer currently ignores the sub pixel precision, so even if you are on a hidpi device, you will not get half pixels.

As per the above comment removing blocker label for this issue, please feel free to add it back if it's a valid one.

Thanks!

Karl, should we close this as working as intended or is there more work you want to do here?

I don't get this. The issue breaks use of subpixel borders (for the browsers which support them) unless special workarounds for chromium are added. 

Not setting an inner background or not using .5px borders for this browser don't sound like solutions.