Make members of Singleton<T> private and only visible to the singleton type.

net/base/x509_certificate_win.cc

 // Copyright (c) 2006-2008 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/base/x509_certificate.h"
 
+#include "base/lazy_instance.h"
 #include "base/logging.h"
 #include "base/pickle.h"
-#include "base/singleton.h"
 #include "base/string_tokenizer.h"
 #include "base/string_util.h"
 #include "base/utf_string_conversions.h"
 #include "net/base/cert_status_flags.h"
 #include "net/base/cert_verify_result.h"
 #include "net/base/ev_root_ca_metadata.h"
 #include "net/base/net_errors.h"
 #include "net/base/scoped_cert_chain_context.h"
 
 #pragma comment(lib, "crypt32.lib")
@@ skipping 502 matching lines @@
     dns_names->push_back(subject_.common_name);
 }
 
 class GlobalCertStore {
  public:
   HCERTSTORE cert_store() {
     return cert_store_;
   }
 
  private:
-  friend struct DefaultSingletonTraits<GlobalCertStore>;
+  friend struct base::DefaultLazyInstanceTraits<GlobalCertStore>;
 
   GlobalCertStore()
       : cert_store_(CertOpenStore(CERT_STORE_PROV_MEMORY, 0, NULL, 0, NULL)) {
   }
 
   ~GlobalCertStore() {
     CertCloseStore(cert_store_, 0 /* flags */);
   }
 
   const HCERTSTORE cert_store_;
 
   DISALLOW_COPY_AND_ASSIGN(GlobalCertStore);
 };
 
+static base::LazyInstance<GlobalCertStore> g_cert_store(
+    base::LINKER_INITIALIZED);
+
 // static
 HCERTSTORE X509Certificate::cert_store() {
-  return Singleton<GlobalCertStore>::get()->cert_store();
+  return g_cert_store.Get().cert_store();
 }
 
 int X509Certificate::Verify(const std::string& hostname,
                             int flags,
                             CertVerifyResult* verify_result) const {
   verify_result->Reset();
   if (!cert_handle_)
     return ERR_UNEXPECTED;
 
   // Build and validate certificate chain.
@@ skipping 297 matching lines @@
   DWORD sha1_size = sizeof(sha1.data);
   rv = CryptHashCertificate(NULL, CALG_SHA1, 0, cert->pbCertEncoded,
                             cert->cbCertEncoded, sha1.data, &sha1_size);
   DCHECK(rv && sha1_size == sizeof(sha1.data));
   if (!rv)
     memset(sha1.data, 0, sizeof(sha1.data));
   return sha1;
 }
 
 }  // namespace net