<rdar://problem/64320995>
Created attachment 402058 [details] Patch
Comment on attachment 402058 [details] Patch Can we ref test this?
Created attachment 402074 [details] Patch
Created attachment 402075 [details] Patch
Committed r263136: <https://trac.webkit.org/changeset/263136> All reviewed patches have been landed. Closing bug and clearing flags on attachment 402075 [details].
As win-ews reported, fast/images/hidpi-image-position-on-device-pixels-with-border-radius.html is consistently failing on Windows with the following image diff: https://build.webkit.org/results/Apple%20Win%2010%20Release%20(Tests)/r263144%20(6742)/fast/images/hidpi-image-position-on-device-pixels-with-border-radius-diffs.html