The skia roll contains, https://skia-review.googlesource.com/c/skia/+/59084, which changes how the GPU draws hairline lines.
This causes the following layout test to change (and be more correct)
* virtual/gpu-rasterization/images/imagemap-focus-ring-in-positioned-container.html
* virtual/gpu-rasterization/images/imagemap-focus-ring-outline-color-explicitly-inherited-from-map.html
* virtual/gpu-rasterization/images/imagemap-focus-ring-outline-color-not-inherited-from-map.html
* virtual/gpu-rasterization/images/imagemap-focus-ring-outline-color.html
* virtual/gpu-rasterization/images/imagemap-focus-ring-with-paint-root-offset.html
* virtual/gpu-rasterization/images/imagemap-focus-ring.html
* virtual/gpu-rasterization/images/imagemap-overflowing-polygon-focus-ring.html
* virtual/gpu-rasterization/images/imagemap-polygon-focus-ring.html
Comment 1 by bugdroid1@chromium.org
, Oct 13 2017