title: Difference for Widget.ProgressBar.Small and Widget.ProgressBar.Small.Inverse
body: <p>I try out two different progress bar styles for action bar button, through </p>
  
  <pre><code>refreshMenuItem.setActionView(R.layout.actionbar_indeterminate_progress);
  </code></pre>
  
  <h2>actionbar_indeterminate_progress.xml</h2>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      style="?attr/actionButtonStyle" &gt;
      &lt;ProgressBar
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          style="@android:style/Widget.ProgressBar.Small" /&gt;
  &lt;/LinearLayout&gt;
  </code></pre>
  
  <p>I had tried <strong>Widget.ProgressBar.Small</strong> and <strong>Widget.ProgressBar.Small.Inverse</strong>. However, I do not see any visual difference.</p>
  
  <h2>Widget.ProgressBar.Small</h2>
  
  <p><img src="https://i.stack.imgur.com/irEPP.png" alt="enter image description here"></p>
  
  <h2>Widget.ProgressBar.Small.Inverse</h2>
  
  <p><img src="https://i.stack.imgur.com/Doc3G.png" alt="enter image description here"></p>
  
  <p>I expect there is an <em>inverse</em> in color but there isn't. Am I missing something?</p>