<!DOCTYPE html>
<head>
<style>
.d1 {
  position: absolute;
  left: 10.5px;
  width: 100px;
  height: 100px;
  background-color: red;
  border: 1px solid green;
}

.d2 {
  background-color: green;
  width: 100%;
  height: 100%;
}
</style>
</head>

<body onload="startTest()">
  <div class="d1"><div class="d2"></div></div>


  <script>
    function startTest() {
      if (window.testRunner) {
        testRunner.waitUntilDone();
        testRunner.setBackingScaleFactor(2, finishTest);
      }
    }

    function finishTest() {
        setTimeout(function() { testRunner.notifyDone() }, 0);
    }
  </script>
</body>