text: // Delete any applied filters
  delete document.body.style.filter;
  delete document.body.style.webkitFilter;
  
  var body = document.body;
  var html = document.documentElement;
  
  function drawLine(ctx, x, y) {
    ctx.lineTo(x, y);
    ctx.stroke();
  }
  
  function drawDot(ctx, x, y) {
    ctx.arc(x, y, 3, 0, 2 * Math.PI, false);
    ctx.stroke();
  }
  
  function getCoordinates(elem) {
      var box = elem.getBoundingClientRect();
      var body = document.body;
      var docEl = document.documentElement;
      var halfWidth = box.width / 2;
      var halfHeight = box.height / 2;
  
      var scrollTop = window.pageYOffset || docEl.scrollTop || body.scrollTop;
      var scrollLeft = window.pageXOffset || docEl.scrollLeft || body.scrollLeft;
  
      var clientTop = docEl.clientTop || body.clientTop || 0;
      var clientLeft = docEl.clientLeft || body.clientLeft || 0;
  
      var top = box.top + scrollTop - clientTop;
      var left = box.left + scrollLeft - clientLeft;
  
    return {
      top: Math.round(top + halfHeight),
      left: Math.round(left + halfWidth)
    };
  }
  
  var height = Math.max(
    body.scrollHeight,
    body.offsetHeight,
    html.clientHeight,
    html.scrollHeight,
    html.offsetHeight
  );
  
  var width = Math.max(
    body.scrollWidth,
    body.offsetWidth,
    html.clientWidth,
    html.scrollWidth,
    html.offsetWidth
  );
  
  var canvas = document.createElement("canvas");
  canvas.id = 'chrome-lens-canvas';
  canvas.style.pointerEvents = 'none';
  canvas.style.top = 0;
  canvas.style.left = 0;
  canvas.height = height;
  canvas.width = width;
  canvas.style.position = 'absolute';
  canvas.style.zIndex = 2147483647;
  
  var ctx = canvas.getContext('2d');
  ctx.strokeStyle = 'red';
  ctx.lineWidth = 2;
  
  ctx.beginPath();
  ctx.moveTo(0, 0);
  
  if (document.activeElement !== document.body) {
    const { top: y, left: x } = getCoordinates(document.activeElement);
    drawLine(ctx, x, y);
  }
  
  document.body.appendChild(canvas);
  
  document.body.onkeyup = function (e) {
      e = e || window.event;
      if (e.keyCode === 9) {
        // Tab
        const { top: y, left: x } = getCoordinates(e.target);
        drawLine(ctx, x, y);
        drawDot(ctx, x, y);
      }
  };
  