@Override
    public void requestLayout() {
        mIsLayoutDirty = true;
        super.requestLayout();
    }
When looking for focus in children of a scroll view, need to be a little
more careful not to give focus to something that is scrolled off screen.

This is more expensive than the default {@link ViewGroup}
implementation, otherwise this behavior might have been made the default.
app/src/main/java/home/smart/fly/animations/widget/NestedScrollView.java