Make DoCanonicalizeIPv6Address safer by changing loop condition and adding a DCHECK
Make DoCanonicalizeIPv6Address safer by changing loop condition and
adding a DCHECK

Patch by yuzo@chromium.org
Original review URL: http://codereview.chromium.org/155077


datacratic/DasDB,datacratic/DasDB,datacratic/DasDB,datacratic/DasDB,datacratic/DasDB