DevBytes: ActionBarCompat (Japanese) - YouTube https://www.youtube.com/watch?v=JApBHLZaNpo#t=335

gistfile1.xml

<!--
  ShareActionProvider
  android.support.v7.widget.ShareActionProvider
-->
<menu xmlns:android="http://schemas/android.com/apk/res/android"
        xmlns:yourapp="http://schemas.android.com/apk/res-auto">
    <item
        android:id="@+id/menu_share"
        android:title="@string/menu_share"
        yourapp:actionProviderClass="android.support.v7.widget.ShareActionProvider"
        yourapp:showAsAction="always" />
</menu>