SupportActionBar Transparent

styles.xml

<!-- Application theme(AppBarLayout and background color transparent). -->
<style name="Theme" parent="Theme.AppCompat.Light">
    <item name="android:actionBarStyle">@style/ActionBar</item>
    <item name="actionBarStyle">@style/ActionBar</item><!-- Support library compatibility -->
</style>

<!-- Style for SupportActionBar -->
<style name="ActionBar" parent="@style/Widget.AppCompat.ActionBar">
    <item name="android:background">@drawable/actionbar_background</item>
    <item name="android:windowActionBarOverlay">true</item>
    <!-- Support library compatibility -->
    <item name="background">@drawable/actionbar_background</item>
    <item name="windowActionBarOverlay">true</item>
</style>