Add a histogram for measuring the number of times we fall back to common name matching, when a cert…

net/cert/x509_certificate.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/cert/x509_certificate.h"
 
 #include <stdlib.h>
 
 #include <algorithm>
 #include <map>
@@ skipping 510 matching lines @@
   // the input name was absolute (included trailing .), normalize it as if it
   // was relative.
   if (!reference_name.empty() && *reference_name.rbegin() == '.')
     reference_name.resize(reference_name.size() - 1);
   if (reference_name.empty())
     return false;
 
   // Allow fallback to Common name matching?
   const bool common_name_fallback = cert_san_dns_names.empty() &&
                                     cert_san_ip_addrs.empty();
+  UMA_HISTOGRAM_BOOLEAN("Net.CertCommonNameFallback", common_name_fallback);
 
   // Fully handle all cases where |hostname| contains an IP address.
   if (host_info.IsIPAddress()) {
     if (common_name_fallback &&
         host_info.family == url_canon::CanonHostInfo::IPV4) {
       // Fallback to Common name matching. As this is deprecated and only
       // supported for compatibility refuse it for IPv6 addresses.
       return reference_name == cert_common_name;
     }
     base::StringPiece ip_addr_string(
@@ skipping 184 matching lines @@
     RemoveFromCache(cert_handle_);
     FreeOSCertHandle(cert_handle_);
   }
   for (size_t i = 0; i < intermediate_ca_certs_.size(); ++i) {
     RemoveFromCache(intermediate_ca_certs_[i]);
     FreeOSCertHandle(intermediate_ca_certs_[i]);
   }
 }
 
 }  // namespace net