net: disable SSLv3 fallback.

This change adds a "minimum fallback version" (TLS 1.0). When doing fallback, versions below this minimum will still be tried but the resulting connection, if successful won't actually be used. Rather Chrome will show a different error message if SSLv3 would have worked.

SSLv3 fallback can still be enabled via a new command line flag for those who need it but it'll be interesting to see how this does on dev and beta.


Review URL:

Cr-Commit-Position: refs/heads/master@{#299567}
13 files changed