function upgradeDomInternal(optJsClass, optCssClass) {
	    if (typeof optJsClass === 'undefined' &&
	        typeof optCssClass === 'undefined') {
	      for (var i = 0; i < registeredComponents_.length; i++) {
	        upgradeDomInternal(registeredComponents_[i].className,
	            registeredComponents_[i].cssClass);
	      }
	    } else {
	      var jsClass = /** @type {string} */ (optJsClass);
	      if (typeof optCssClass === 'undefined') {
	        var registeredClass = findRegisteredClass_(jsClass);
	        if (registeredClass) {
	          optCssClass = registeredClass.cssClass;
	        }
	      }

	      var elements = document.querySelectorAll('.' + optCssClass);
	      for (var n = 0; n < elements.length; n++) {
	        upgradeElementInternal(elements[n], jsClass);
	      }
	    }
	  }
Handle change of state.

@param {Event} event The event that fired.
@private