ActionBarActivity is now deprecated..
Check out what Google says about using AppCombat.
The AppCompat Support Library started with humble, but important beginnings: a single consistent Action Bar for all API 7 and higher devices. In revision 21, it took on new responsibility: bringing material color palette, widget tinting, Toolbar support, and more to all API 7+ devices. With that, the name ActionBarActivity didn’t really cover the full scope of what it really did.
In this release, ActionBarActivity has been deprecated in favor of the new AppCompatActivity. However, this wasn’t just a rename. In fact, the internal logic of AppCompat is now available via AppCompatDelegate – a class you can include in any Activity, hook up the appropriate lifecycle methods, and get the same consistent theming, color tinting, and more without requiring you to use AppCompatActivity (although that remains the easiest way to get started).
With the help of the new AppCompatDelegate, we’ve also added support for consistent, material design dialogs via the AppCompatDialog class. If you’ve used AlertDialog before, you’ll be happy to know there is also now a Support Library version in support.v7.app.AlertDialog, giving you the same API as well as all the benefits of AppCompatDialog.
The ability to tint widgets automatically when using AppCompat is incredibly helpful in keeping strong branding and consistency throughout your app. This is done automatically when inflating layouts – replacing Button with AppCompatButton, TextView with AppCompatTextView, etc. to ensure that each could support tinting. In this release, those tint aware widgets are now publicly available, allowing you to keep tinting support even if you need to subclass one of the supported widgets.
The full list of tint aware widgets at this time is:
AppCompatAutoCompleteTextView
AppCompatButton
AppCompatCheckBox
AppCompatCheckedTextView
AppCompatEditText
AppCompatMultiAutoCompleteTextView
AppCompatRadioButton
AppCompatRatingBar
AppCompatSpinner
AppCompatTextView
Lollipop added the ability to overwrite the theme at a view by view level by using the android:theme XML attribute – incredibly useful for things such as dark action bars on light activities. Now, AppCompat allows you to use android:theme for Toolbars (deprecating the app:theme used previously) and, even better, brings android:theme support to all views on API 11+ devices.
If you’re just getting started with AppCompat, check out how easy it is to get started and bring a consistent design to all of your users:
You can read more from Android Developers blog here…
http://android-developers.blogspot.in/2015/04/android-support-library-221.html