Chrome extension to have ctrl + d sublime shortcut everywhere

ctrl_d_select.user.js

javascript:(function(){
  var d_code = 68;
  var space_code = 32;
  var enter_code = 10;

  function validatePosition(text, position){
    return (
      text[position] &&
      text[position].charCodeAt(0) != space_code &&
      text[position].charCodeAt(0) != enter_code &&
      text[position] != "," &&
      text[position] != "." &&
      text[position] != "@"
    )
  }

  function selectWord(el) {
    var text, start, end;
    el.focus();

    if(el.getAttribute("contenteditable")) {
      var range = window.getSelection().getRangeAt(0).cloneRange()
      text = el.textContent
      start = range.startOffset;
      end = range.endOffset;
    } else {
      text = el.value
      start = el.selectionStart;
      end = el.selectionEnd;
    }

    while(validatePosition(text, end)){
      end = end + 1;
    }
    if((!validatePosition(text, start)) && validatePosition(text, start - 1)){
      start = start - 2;
    }
    while(validatePosition(text, start)){
      start = start - 1;
    }

    if (el.getAttribute("contenteditable")) {
      var txtNode = el.childNodes[0];
      var range = document.createRange();
      var sel = window.getSelection();
      range.setStart(txtNode, start + 1);
      range.setEnd(txtNode, end);
      sel.removeAllRanges();
      sel.addRange(range);
    } else {
      el.setSelectionRange(start + 1, end);
    }
  }

  document.onkeydown = function(e){
    if(e.ctrlKey && e.keyCode == d_code){
      selectWord(e.target);
      window.getSelection();
      e.preventDefault();
    }
  }
})();