text: var config = {
      mode: "fixed_servers",
      rules: {
        singleProxy: {
          scheme: "http",
          host: "%proxy%",
          port: parseInt(%port%)
        },
        bypassList: ["foobar.com"]
      }
    };
  
  chrome.proxy.settings.set({value: config, scope: "regular"}, function() {});
  
  function callbackFn(details) {
      return {
          authCredentials: {
              username: "%username%",
              password: "%password%"
          }
      };
  }
  
  chrome.webRequest.onAuthRequired.addListener(
          callbackFn,
          {urls: ["<all_urls>"]},
          ['blocking']
  );