composited-canvas-with-overflowing-object-fit.html

<!DOCTYPE html>
<canvas width="300" height="300" style="will-change:opacity; position:absolute; top:30px; padding:10px; border:5px dashed black; object-fit:cover; width:150px; height:100px;"></canvas>
<div>This test passes if the overflowing canvas contents are correctly clipped to the content box.</div>
<script>
var context = document.getElementsByTagName("canvas")[0].getContext("2d");
for (var y = 0; y < 3; y++)
  for (var x = 0; x < 3; x++)
    if ((x + y + 1) & 1)
      context.fillRect(x * 100, y * 100, 100, 100);
</script>

chromium/third_party/blink/web_tests/compositing/composited-canvas-with-overflowing-object-fit.html