How to make a "progressbar" similar to Gmail or G+?

How to make a "progressbar" similar to Gmail or G+?


I could add a simple progressbar to XML activity and put a padding /
margin negative, but I think Google inserted directly into the actionbar
progressbar.
If I do something like this:
Activity act = this;
act.setProgress (20 * 100);
...
In the action bar displays a spinner, but I'm interested in one horizontal
style bar as does Google. What is the best solution?
I am using android-support-v7 to be compatible with older versions (I'm
not interested in using libraries like ActionBarSherlock)