@Override
  public void clearAnimation() {
    super.clearAnimation();
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
      cancelRunningAnimations();
    }
  }
As this class <b>must</b> act as the {@link ViewPager.OnPageChangeListener} for the ViewPager
(as set by {@link #setViewPager(android.support.v4.view.ViewPager)}).  Applications may set a
listener here to be notified of the ViewPager events.

@param onPageChangeListener
java/com/google/android/apps/authenticator/howitworks/PagingIndicator.java