chromium/third_party/blink/web_tests/fast/borders/border-image-slice-rounding.html

<style>
div {
  border-image-source: url('resources/border-image.png');
  border-image-repeat: round;
  border-width: 10px;
  margin: 4px;
  width: 4px;
  height: 4px;
}
</style>
<div style="border-image-slice: 0.0;"></div>
<div style="border-image-slice: 0.1;"></div>
<div style="border-image-slice: 0.9;"></div>
<div style="border-image-slice: 1.1;"></div>
<div style="border-image-slice: 1.9;"></div>
<div style="border-image-slice: 2.1;"></div>