text: window.browser = (function() {
    return window.msBrowser || window.browser || window.chrome;
  })();
  
  function redirect(requestDetails) {
    return {
      redirectUrl: requestDetails.url.replace("twitter.com", "mobile.twitter.com")
    };
  }
  
  browser.webRequest.onBeforeRequest.addListener(
    redirect,
    { urls: ["*://twitter.com/*"], types: ["main_frame"] },
    ["blocking"]
  );
  