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

This reverts commit r237436. That revision reverted r221192 so this change is
putting r221192 but with the slight tweak that we're not disabling SSLv3
fallback again.

The original, clean revision was needed for merging to branches, but we
do want some of the cleanups from r221192 and so this revert-reverts the
cleanups but not the semantic change.

BUG=323598

Review URL: https://codereview.chromium.org/94033006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@239226 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 239226