Is there a way to keep execCommand("insertHTML") from removing attributes in chrome?

function isOrIsAncestorOf(ancestor, descendant) {
  var n = descendant;
  while (n) {
    if (n === ancestor) {
      return true;
    } else {
      n = n.parentNode;
    }
  }
  return false;
}

function nodeContainsSelection(node) {
  var sel, range;
  if (window.getSelection && (sel = window.getSelection()).rangeCount) {
    range = sel.getRangeAt(0);
    return isOrIsAncestorOf(node, range.commonAncestorContainer);
  }
  return false;
}

function insertHTML() {
  var sel, range;
  if (window.getSelection && (sel = window.getSelection()).rangeCount) {
    range = sel.getRangeAt(0);
    range.collapse(true);
    var span = document.createElement("span");
    span.id = "myId";
    span.appendChild( document.createTextNode("hi") );
    range.insertNode(span);

    // Move the caret immediately after the inserted span
    range.setStartAfter(span);
    range.collapse(true);
    sel.removeAllRanges();
    sel.addRange(range);
  }
}

window.onload = function() {
  document.getElementById("inserter").onmousedown = function() {
    var editor = document.getElementById("editor");
    if (nodeContainsSelection(editor)) {
      insertHTML();
      return false;
    }
  };
};

span {
  font-weight: bold;
  color: green;
}

<input type="button" id="inserter" value="Insert span">
<div contenteditable="true" id="editor">
    some content
</div>