title: unable create autoupdate for an google chrome extension
body: <p>I am Developing a google chrome extension. I need to provide the auto update for my extension.I am also following the <strong>developer.chrome.com/extensions/autoupdate</strong> but  my extension is not updating  I am trying with command   <strong>--extensions-update-frequency</strong>  and i will also check with the <code>chrome.runtime.requestUpdateCheck()</code> it   returns status as <strong>'throttled'</strong>
  my manifest file:</p>
  
  <pre><code>   {
    "manifest_version":2,
    "name":"Notification",
    "description": "To notify the Mail count",
    "version": "1.0",
     "update_url": "http://localhost/ext/updates.xml",
  "background": {
    "scripts":["popup.js"]
    },
      "browser_action": {
      "default_icon": "icon.png",
      "default_popup":"popup.html"
    },
      "icons": {
      "256": "icon.png"
    },
    "permissions": [
      "tabs",
    "bookmarks",
    "http://*/*",
    "https://*/*",
    "unlimitedStorage",
    "background",
    "notifications"
    ]
  }
  </code></pre>
  
  <p>and my updates.xml :</p>
  
  <pre><code>&lt;?xml version='1.0' encoding='UTF-8'?&gt;
  &lt;gupdate xmlns='http://www.google.com/update2/response' protocol='2.0'&gt;
    &lt;app appid='eimjaaebemfnanomhcgnljegahiiffdk'&gt;
      &lt;updatecheck codebase='http://localhost/ext/note_v2.crx' version='2.0' /&gt;
    &lt;/app&gt;
  &lt;/gupdate&gt;
  </code></pre>
  
  <p>and my new extension is also in same directory..</p>
  
  <p>Please any one help me</p>
  
  <p>Thanks in advance..............</p>