When using a SwipeRefreshLayout in combination with a overlay mode ActionBar, the loading animation will be displayed behind the actionbar, making it almost invisible.
I have currently come across this when I upgraded my dependency from appcompat 19.1.0 to 21.0.0 and made no code changes.
This is actually a known issue with SwipeRefreshLayout in appcompat 21.0.0.
Look here for a workaround: https://code.google.com/p/android/issues/detail?id=77712