You should just be usingmLayout.getViewTreeObserver()inonGlobalLayout(), rather than trying to access the_old_one. Eg.

mLayout.getViewTreeObserver().addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
    public void onGlobalLayout() {
        scrollToGridPos(getCenterPoint(), false);
        mLayout.getViewTreeObserver().removeGlobalOnLayoutListener(this);        
    }
});