title: chrome.webRequest.onBeforeRequest.addListener function not being called
body: <p>So I'm trying to make an extension that if you put a twitter username in the address bar and press enter, it will go to that twitter page instead of going to google, but it doesn't even trigger the function no matter what I enter in the address bar.</p>
  
  <p>Manifest</p>
  
  <pre><code>{
    "manifest_version": 2,
  
    "name": "Twitter link",
    "description": "Type in a username with @ preceding it to go to that twitter page, ex: @wol_lay would go to https://twitter.com/wol_lay",
    "version": "1.0",
  
    "permissions": [
      "webRequest",
      "webRequestBlocking",
      "*://*.google.com"
    ],
    "background": {"scripts": ["background.js"]}
  }
  </code></pre>
  
  <p>My code</p>
  
  <pre><code>chrome.webRequest.onBeforeRequest.addListener(
    function(details)
    {
      console.log (details.url);
      if (details.url.charAt (0) == '@')
      {
        return {redirectUrl: "https://www.twitter.com/" + details.url.substring(1,details.url.length - 1)};
      }
    },
  
    {urls: ["&lt;all_urls&gt;"]},
  
    ["blocking"]
  );
  </code></pre>