Revert: "net: don't allow SSLv3 fallback for Google properties."

This reverts r221192.

We are going to try a different approach. See
http://www.ietf.org/mail-archive/web/tls/current/msg10676.html

BUG=323598

Review URL: https://codereview.chromium.org/88913003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@237436 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 237436