chromium/third_party/blink/web_tests/virtual/forced-high-contrast-colors/fast/css/forced-colors-mode/forced-colors-mode-15.html

<!DOCTYPE html>
<meta charset="utf-8">
<title>
  Forced colors mode - inactive selection.
</title>
<link rel="help" href="https://www.w3.org/TR/css-color-adjust-1/#forced-colors-properties">
<link rel=match href="forced-colors-mode-15-expected.html">
<style>
  br::selection:window-inactive {
    background-color: transparent;
    forced-color-adjust: none;
  }
  span {
    /* inline-block to ensure the selection bounding rectangle matches that of the
       span. This allows us to test selection using a reference test. */
    display: inline-block;
  }
  .select::selection:window-inactive {
    background-color: rgba(255, 0, 0, 0.99); /* alpha < 1 so that we don't blend the background color with white. */
    color: blue;
  }
  #adjust-none {
    forced-color-adjust: none;
  }
  #adjust-none-on-highlight::selection:window-inactive {
    forced-color-adjust: none;
  }

  <!--
  "
  The forced-color-adjust property cannot be set on highlight pseudo-elements;
  however a highlight pseudo-element must honor any forced colors mode applied
  to its originating element (and is therefore subject to the control of the
  originating element’s forced-color-adjust value).
  "
  coming from
  https://www.w3.org/TR/css-pseudo-4/#highlight-styling
  -->

</style>
<body>
  <div id="adjust-none">
    <span class="select">AAA</span>
  </div>
  <span id="adjust-none-on-highlight" class="select">AAA</span>
</body>

<script>
  function runTest() {
    var node1 = document.getElementsByClassName('select')[0].firstChild;
    var node2 = document.getElementsByClassName('select')[1].firstChild;
    var range = document.createRange();
    range.setStart(node1, 0);
    range.setEnd(node2, node2.length);
    window.getSelection().addRange(range);
    if (window.testRunner) {
      testRunner.setWindowFocus(false);
      setTimeout(function() { testRunner.notifyDone(); }, 0);
    }
  }

  if (window.testRunner) {
    testRunner.waitUntilDone();
    // Add some delay to avoid the initial focus event.
    setTimeout(runTest, 100);
  }
</script>