title: Dropdown in ActionBar backwards compatibilty
body: <p>I would like to use a dropdown (spinner) in my actionbar, like in the image below. But I'm wondering about the backwards compatibility (<code>android &lt; 3</code> ). </p>
  
  <p><img src="https://i.stack.imgur.com/4nk4k.png" alt="Dropdown"></p>
  
  <p>Is there any kind of native backwards compatibility, like with the menu-items in the action bar, or is using a 3rd party library (like <a href="http://actionbarsherlock.com" rel="nofollow noreferrer">actionbarsherlock</a>) my only option?</p>