check for null item in web history in saveState

        ArrayList<byte[]> history = new ArrayList<byte[]>(size);

        for (int i = 0; i < size; i++) {

            WebHistoryItem item = list.getItemAtIndex(i);

            if (null == item) {

                // FIXME: this shouldn't happen

                // need to determine how item got set to null

                Log.w(LOGTAG, "saveState: Unexpected null history item.");

                return null;

            }

            byte[] data = item.getFlattenedData();

            if (data == null) {

                // It would be very odd to not have any data for a given history