title: Get rid of ActionBar shadow over SlidingTabLayout
body: <p>I'm porting my app to appcompat21, using SlidingTabLayout for tabs in an ActionBarActivity. The Action bar is casting a shadow over the tab strip, and I can't figure out how to get rid of it:<img src="https://i.stack.imgur.com/W6523.png" alt="enter image description here"></p>
  
  <p>Here's what I have:</p>
  
  <pre><code> &lt;style name="MyActionBar" parent="@style/Widget.AppCompat.ActionBar"&gt;
       &lt;item name="background"&gt;@color/app_primary&lt;/item&gt;
       &lt;item name="android:background"&gt;@color/app_primary&lt;/item&gt;
       &lt;item name="backgroundSplit"&gt;@color/black&lt;/item&gt;
       &lt;item name="android:backgroundSplit"&gt;@color/black&lt;/item&gt;
       &lt;item name="android:elevation"&gt;0dp&lt;/item&gt;
   &lt;/style&gt;
  </code></pre>
  
  <p>I've also tried</p>
  
  <pre><code>     &lt;item name="android:windowContentOverlay"&gt;@null&lt;/item&gt;
  </code></pre>
  
  <p>I got the shadow <em>under</em> the tab bar by setting its elevation in the layout file, but now I have two shadows...
  Any idea how to fix this?</p>