Normalize hostnames before searching for HSTS/HPKP preloads
The HSTS/HPKP preload set is pre-normalized at construction time.
Since the queries come from the GURL, not from the DNS layer,
we need to normalize the hostname before scanning for preloads.
This used to be handled by CanonicalizeHost(), which used the
same mechanism as the resolver, but the storage of the preloads
has changed to be more efficient, and thus no longer uses the