src/core/vendor.js

import "document";

function d3_vendorSymbol(object, name) {
  if (name in object) return name;
  name = name.charAt(0).toUpperCase() + name.substring(1);
  for (var i = 0, n = d3_vendorPrefixes.length; i < n; ++i) {
    var prefixName = d3_vendorPrefixes[i] + name;
    if (prefixName in object) return prefixName;
  }
}

var d3_vendorPrefixes = ["webkit", "ms", "moz", "Moz", "o", "O"];