title: chrome.identity.getAuthToken not working
body: <p>I am working with Chrome Identity API, to provide users with a Google Authentication on my Chrome Extension.</p>
  
  <p>I followed the official tutorial of Google :  <a href="https://developer.chrome.com/apps/app_identity">link Chrome Identity API</a> </p>
  
  <ul>
  <li>i added permissions to <strong>manifest.json</strong> and <strong>Client ID</strong> and <strong>Scopes</strong></li>
  <li>to trigger the Authentification i added this code in my <strong>Background.js</strong> </li>
  </ul>
  
  <blockquote>
    <p><strong><em>chrome.identity.getAuthToken</em></strong></p>
  </blockquote>
  
  <p>The problem is when i execute the extension i am redirected to this login page </p>
  
  <blockquote>
    <p><strong>chrome://chrome-signin/?source=5</strong></p>
  </blockquote>
  
  <p>but after a successfull authentication i am redirected another time to the login page </p>
  
  <p>what is the problem ?</p>
  
  <p>Manifest.json</p>
  
  <pre><code>{
    "name": "My Extension",
    "short_name": "Ex App",
    "version": "0.1",
    "description": "description",
    "manifest_version": 2,
    "icons": { "128": "ICONE.png", "48": "ICONE1.png" },
    "permissions": ["contextMenus", "identity", "cookies", "http://*/*",   "https://*/*", "&lt;all_urls&gt;", "unlimitedStorage"],
    "browser_action": {
      "default_title": "Title",
      "default_icon": "imgIcone.png"
    },
    "oauth2": {
          "client_id": "xxxxxxx",
          "scopes": [
              "https://www.googleapis.com/auth/userinfo.email"
      ]   
  },   
  
    "background": {
      "scripts": ["background.js"]
    },
  
      "content_scripts"   : [
  {
    "matches": ["*://*.google.com/*"],
    "js": ["gadget/js/jquery.js","gadget/js/contactcard.js"],
    "css": ["gadget/css/contactcard.css"],
    "all_frames": true
    }],  
  
    "content_security_policy": "script-src 'self' 'unsafe-eval' https://apis.google.com/; object-src 'self'",
    "web_accessible_resources": ["img.png","gadget/css/contactcard.css","gadget/img/extension/crec.png"]
  }
  </code></pre>
  
  <p>Background.js: </p>
  
  <pre><code>chrome.identity.getAuthToken({ 'interactive': true }, function(token) {
          // Use the token.
          console.log(token); 
              });
  </code></pre>