window.Polymer

polymer-bootstrap.js

window.Polymer = function(prototype) {
      var ctor = desugar(prototype);
      // Polymer.Base is now chained to ctor.prototype, and for IE10 compat
      // this may have resulted in a new prototype being created
      prototype = ctor.prototype;
      // native Custom Elements treats 'undefined' extends property
      // as valued, the property must not exist to be ignored
      var options = {
        prototype: prototype
      };
      if (prototype.extends) {
        options.extends = prototype.extends;
      }
      Polymer.telemetry._registrate(prototype);
      document.registerElement(prototype.is, options);
      return ctor;
    };