Align SSLClientSocketOpenSSL and SSLClientSocketNSS histograms.

net/socket/ssl_client_socket_nss.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This file includes code SSLClientSocketNSS::DoVerifyCertComplete() derived
 // from AuthCertificateCallback() in
 // mozilla/security/manager/ssl/src/nsNSSCallbacks.cpp.
 
 /* ***** BEGIN LICENSE BLOCK *****
  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
@@ skipping 2438 matching lines @@
                                         &peer_supports_renego_ext);
   if (ok == SECSuccess) {
     if (!peer_supports_renego_ext) {
       nss_handshake_state_.ssl_connection_status |=
           SSL_CONNECTION_NO_RENEGOTIATION_EXTENSION;
       // Log an informational message if the server does not support secure
       // renegotiation (RFC 5746).
       VLOG(1) << "The server " << host_and_port_.ToString()
               << " does not support the TLS renegotiation_info extension.";
     }
-    UMA_HISTOGRAM_ENUMERATION("Net.RenegotiationExtensionSupported",
-                              peer_supports_renego_ext, 2);
-
-    // We would like to eliminate fallback to SSLv3 for non-buggy servers
-    // because of security concerns. For example, Google offers forward
-    // secrecy with ECDHE but that requires TLS 1.0. An attacker can block
-    // TLSv1 connections and force us to downgrade to SSLv3 and remove forward
-    // secrecy.
-    //
-    // Yngve from Opera has suggested using the renegotiation extension as an
-    // indicator that SSLv3 fallback was mistaken:
-    // tools.ietf.org/html/draft-pettersen-tls-version-rollback-removal-00 .
-    //
-    // As a first step, measure how often clients perform version fallback
-    // while the server advertises support secure renegotiation.
-    if (ssl_config_.version_fallback &&
-        channel_info.protocolVersion == SSL_LIBRARY_VERSION_3_0) {
-      UMA_HISTOGRAM_BOOLEAN("Net.SSLv3FallbackToRenegoPatchedServer",
-                            peer_supports_renego_ext == PR_TRUE);

[Ryan Sleevi, 2014/08/20 19:58:12]

Adam should comment on this. I think I'm fine removing this, in light of the
fallback scsv.

[agl, 2014/08/22 18:26:32]

LGTM. I don't that we need to worry about this any more - the numbers suggest
that it's never going to work.

-    }
   }
 
   if (ssl_config_.version_fallback) {
     nss_handshake_state_.ssl_connection_status |=
         SSL_CONNECTION_VERSION_FALLBACK;
   }
 }
 
 void SSLClientSocketNSS::Core::UpdateNextProto() {
   uint8 buf[256];
@@ skipping 1053 matching lines @@
 scoped_refptr<X509Certificate>
 SSLClientSocketNSS::GetUnverifiedServerCertificateChain() const {
   return core_->state().server_cert.get();
 }
 
 ChannelIDService* SSLClientSocketNSS::GetChannelIDService() const {
   return channel_id_service_;
 }
 
 }  // namespace net