title: Cannot use prompt() or alert() in the window opened with chrome.identity.launchWebAuthFlow()
body: <p>I am trying to implement authentication in my Chrome extension. I am using the chrome identity API with <code>chrome.identity.launchWebAuthFlow</code> but the window opened does not display any of my alerts or prompt.
  Here is my manifest</p>
  <pre class="lang-json prettyprint-override"><code>{
    &quot;manifest_version&quot;: 2,
    &quot;name&quot;: &quot;MyApp&quot;,
    &quot;version&quot;: &quot;1.0.0&quot;,
    &quot;description&quot;: &quot;My cool app&quot;,
    &quot;short_name&quot;: &quot;MyApp&quot;,
    &quot;permissions&quot;: [
      &quot;activeTab&quot;,
      &quot;declarativeContent&quot;,
      &quot;storage&quot;,
      &quot;&lt;all_urls&gt;&quot;,
      &quot;bookmarks&quot;,
      &quot;identity&quot;,
      &quot;https://auth.server.com/*&quot;
    ],
    &quot;content_scripts&quot;: [
      {
        &quot;matches&quot;: [
          &quot;&lt;all_urls&gt;&quot;
        ],
        &quot;css&quot;: [
          &quot;style.css&quot;
        ],
        &quot;js&quot;: [
          &quot;main.js&quot;
        ]
      }
    ],
    &quot;background&quot;: {
      &quot;scripts&quot;: [
        &quot;main.js&quot;
      ]
    },
    &quot;browser_action&quot;: {
      &quot;default_title&quot;: &quot;MyApp&quot;,
      &quot;default_popup&quot;: &quot;index.html&quot;
    }
  }
  </code></pre>
  <p>My js code</p>
  <pre class="lang-js prettyprint-override"><code>function init() {
     alert(&quot;Hello World from WebAuthFlow Page&quot;);
  }
  
  init();
  </code></pre>
  <p>I wonder of the window opened for that purpose restricts the window/browser APIs we have access to ?</p>