chromium/third_party/blink/web_tests/fast/spatial-navigation/snav-overlapping-elements.html

<!DOCTYPE html>
<style>
  body a {
    position: absolute;
    height: 100px;
    width: 100px;
    border: 1px solid black;
  }

  #e1 {
    left: 10px;
    top: 10px;
  }

  #e2 {
    left: 20px;
    top: 75px;
  }

  #e3 {
    left: 10px;
    top: 150px;
  }

  #e4 {
    left: 10px;
    top: 300px;
  }

  #e5 {
    left: 75px;
    top: 300px;
  }

  #e6 {
    left: 150px;
    top: 300px;
  }
</style>

<p id="description">This test ensures that Spatial Navigation works with overlapping elements.</p>
<div id="elements">
  <!-- Vertical: -->
  <a id="e1" href="#e1">Element 1</a>
  <a id="e2" href="#e2">Element 2</a>
  <a id="e3" href="#e3">Element 3</a>
  <!-- Horizontal: -->
  <a id="e4" href="#e1">Element 4</a>
  <a id="e5" href="#e2">Element 5</a>
  <a id="e6" href="#e3">Element 6</a>
</div>

<script src="../../resources/testharness.js"></script>
<script src="../../resources/testharnessreport.js"></script>
<script src="resources/snav-testharness.js"></script>
<script type="application/javascript">
  var resultMap = [
    // Vertical:
    ["Down", "e2"],
    ["Down", "e3"],
    ["Up", "e2"],
    ["Up", "e1"],
    ["Down", "e2"],
    ["Down", "e3"],
    ["Down", "e4"],
    // Horizontal:
    ["Right", "e5"],
    ["Right", "e6"],
    ["Left", "e5"],
    ["Left", "e4"]
  ];

  // starting the test itself: get to a known place.
  document.getElementById("e1").focus();
  snav.assertFocusMoves(resultMap);
</script>