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

printing/backend/print_backend_cups.cc

 // Copyright (c) 2010 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 "printing/backend/print_backend.h"
 
 #include <dlfcn.h>
 #include <errno.h>
 #if !defined(OS_MACOSX)
 #include <gcrypt.h>
 #endif
 #include <pthread.h>
 
 #include "base/file_util.h"
+#include "base/lazy_instance.h"
 #include "base/lock.h"
 #include "base/logging.h"
-#include "base/singleton.h"
 #include "base/string_number_conversions.h"
 #include "base/values.h"
 #include "googleurl/src/gurl.h"
 #include "printing/backend/cups_helper.h"
 
 #if !defined(OS_MACOSX)
 GCRY_THREAD_OPTION_PTHREAD_IMPL;
 
 namespace {
 
@@ skipping 31 matching lines @@
     if (!pgnutls_global_init) {
       LOG(ERROR) << "Could not find " << kGnuTlsInitFuncName
                  << " in " << kGnuTlsFile;
       return;
     }
     if ((*pgnutls_global_init)() != 0)
       LOG(ERROR) << "Gnutls initialization failed";
   }
 };
 
+static base::LazyInstance<GcryptInitializer> g_gcrypt_initializer(
+    base::LINKER_INITIALIZED);
+
 }  // namespace
 #endif
 
 namespace printing {
 
 static const char kCUPSPrinterInfoOpt[] = "printer-info";
 static const char kCUPSPrinterStateOpt[] = "printer-state";
 static const char kCUPSPrintServerURL[] = "print_server_url";
 
 class PrintBackendCUPS : public PrintBackend {
@@ skipping 102 matching lines @@
   for (it = printer_list.begin(); it != printer_list.end(); ++it)
     if (it->printer_name == printer_name)
       return true;
   return false;
 }
 
 scoped_refptr<PrintBackend> PrintBackend::CreateInstance(
     const DictionaryValue* print_backend_settings) {
 #if !defined(OS_MACOSX)
   // Initialize gcrypt library.
-  Singleton<GcryptInitializer>::get();
+  g_gcrypt_initializer.Get();
 #endif
 
   std::string print_server_url_str;
   if (print_backend_settings) {
     print_backend_settings->GetString(kCUPSPrintServerURL,
                                       &print_server_url_str);
   }
   GURL print_server_url(print_server_url_str.c_str());
   return new PrintBackendCUPS(print_server_url);
 }
@@ skipping 48 matching lines @@
                    << ", content length: " << content_len;
         file_util::Delete(ppd_path, false);
         ppd_path.clear();
       }
     }
   }
   return ppd_path;
 }
 
 }  // namespace printing