Implement TLS_FALLBACK_SCSV for SSLClientSocketOpenSSL.
In doing so, fix a bug in tlslite's TLS_FALLBACK_SCSV support; the fallback
alert should be sent with the client's version. Otherwise OpenSSL reports
SSL_R_UNSUPPORTED_PROTOCOL and doesn't report the alert. This behavior is
probably not wrong as, if the server responds with a TLS version higher than
what is supported, we can't really be sure of the parse.
BUG=388425
Review URL: https://codereview.chromium.org/
418553003
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@285764 0039d316-1c4b-4281-b951-d872f2087c98