title: Adding shadow below TabBar - Material Design
body: <p>I have an actionbar and tab bar. I removed shadow below actionbar with</p>
  
  <pre><code>&lt;item name="android:windowContentOverlay"&gt;@null&lt;/item&gt;
  </code></pre>
  
  <p>Though, I want to add shadow under tab bar. I'm using SlidingTabLayout. My tab TextView:</p>
  
  <pre><code>&lt;TextView xmlns:android="http://schemas.android.com/apk/res/android"
  android:id="@+id/tabText"
  android:layout_width="wrap_content"
  android:layout_height="@dimen/actionbar_height"
  android:textColor="@color/tab_color"
  android:gravity="center"
  android:textAllCaps="true"
  android:singleLine="true" /&gt;
  </code></pre>
  
  <p>How to do that?</p>