Difference for Widget.ProgressBar.Small and Widget.ProgressBar.Small.Inverse
<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="http://i.stack.imgur.com/irEPP.png" alt="enter image description here"></p>

<h2>Widget.ProgressBar.Small.Inverse</h2>

<p><img src="http://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>
