Add a dedicated SSL protocol version metric.

net/socket/ssl_client_socket_pool.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.
 
 #include "net/socket/ssl_client_socket_pool.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/metrics/field_trial.h"
 #include "base/metrics/histogram.h"
@@ skipping 483 matching lines @@
 
     UMA_HISTOGRAM_CUSTOM_TIMES("Net.SSL_Connection_Latency_2",
                                connect_duration,
                                base::TimeDelta::FromMilliseconds(1),
                                base::TimeDelta::FromMinutes(1),
                                100);
 
     SSLInfo ssl_info;
     ssl_socket_->GetSSLInfo(&ssl_info);
 
+    UMA_HISTOGRAM_ENUMERATION("Net.SSLVersion", SSLConnectionStatusToVersion(
+                                                    ssl_info.connection_status),
+                              SSL_CONNECTION_VERSION_MAX);
+
     UMA_HISTOGRAM_SPARSE_SLOWLY("Net.SSL_CipherSuite",
                                 SSLConnectionStatusToCipherSuite(
                                     ssl_info.connection_status));
 
     UMA_HISTOGRAM_BOOLEAN(
         "Net.RenegotiationExtensionSupported",
         (ssl_info.connection_status &
          SSL_CONNECTION_NO_RENEGOTIATION_EXTENSION) == 0);
 
     if (ssl_info.handshake_type == SSLInfo::HANDSHAKE_RESUME) {
@@ skipping 334 matching lines @@
   CHECK(it != messenger_map_.end());
   delete it->second;
   messenger_map_.erase(it);
 }
 
 void SSLClientSocketPool::OnSSLConfigChanged() {
   FlushWithError(ERR_NETWORK_CHANGED);
 }
 
 }  // namespace net