chromium/third_party/blink/web_tests/fast/sub-pixel/sub-pixel-border-overflow.html

<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <title>Test rendering of sub-pixel borders</title>
    <style>
      .padding {
        padding: 1px;
      }
      .test {
        margin-top: 0.5px;
        border-top: 1.5px solid green;
      }
    </style>
  </head>
  <body>
    <div class=padding>
      <div class=test></div>
    </div>
    <p>
      The border should not overflow the border box.  On devices with
      device pixel ratio 1, there should be a one pixel wide line
      above.
    </p>
  </body>
</html>