Change the bad-certificate handler for SSL (using NSS) to return an

      error.

This requires a few additional changes in the rest of the code. In
particular, we now have to teach HttpNetworkTransaction about how to
restart connections with bad certificates. This was originally
intended to be done by ReconnectIgnoringLastError(), but that API
turns out be very difficult to implement in the SSLClientSocket. So,
instead, we just create a completely new SSLClientSocket.

We also have to be careful to store a copy of the certificate from
within the bad-certificate handler, as it won't be available by the
time GetSSLInfo() is called.

And we fix a bug that would cause us to erroneously talk SSL on
reconnected TCP sockets, even though we were still supposed to
negotiate a proxy tunnel first.

Review URL: http://codereview.chromium.org/43115

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@12809 0039d316-1c4b-4281-b951-d872f2087c98