code: function pollGecko(node) {
      var hasRules;
  
      try {
        // We don't really need to store this value or ever refer to it again, but
        // if we don't store it, Closure Compiler assumes the code is useless and
        // removes it.
        hasRules = !!node.sheet.cssRules;
      } catch (ex) {
        // An exception means the stylesheet is still loading.
        pollCount += 1;
  
        if (pollCount < 200) {
          setTimeout(function () { pollGecko(node); }, 50);
        } else {
          // We've been polling for 10 seconds and nothing's happened. Stop
          // polling and finish the pending requests to avoid blocking further
          // requests.
          hasRules && finish('css');
        }
  
        return;
      }
  
      // If we get here, the stylesheet has loaded.
      finish('css');
    }
docs: Begins polling to determine when the specified stylesheet has finished loading
  in Gecko. Polling stops when all pending stylesheets have loaded or after 10
  seconds (to prevent stalls).
  
  Thanks to Zach Leatherman for calling my attention to the @import-based
  cross-domain technique used here, and to Oleg Slobodskoi for an earlier
  same-domain implementation. See Zach's blog for more details:
  http://www.zachleat.com/web/2010/07/29/load-css-dynamically/
  
  @method pollGecko
  @param {HTMLElement} node Style node to poll.
  @private