Move Singleton and related structs to namespace base

chrome/browser/password_manager/password_store_factory.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 "chrome/browser/password_manager/password_store_factory.h"
 
 #include "base/command_line.h"
 #include "base/environment.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/prefs/pref_service.h"
@@ skipping 153 matching lines @@
   PasswordStoreFactory* factory = GetInstance();
   PasswordStoreService* service = static_cast<PasswordStoreService*>(
       factory->GetServiceForBrowserContext(profile, true));
   if (!service)
     return nullptr;
   return service->GetPasswordStore();
 }
 
 // static
 PasswordStoreFactory* PasswordStoreFactory::GetInstance() {
-  return Singleton<PasswordStoreFactory>::get();
+  return base::Singleton<PasswordStoreFactory>::get();
 }
 
 // static
 void PasswordStoreFactory::OnPasswordsSyncedStatePotentiallyChanged(
     Profile* profile) {
   scoped_refptr<PasswordStore> password_store =
       GetForProfile(profile, ServiceAccessType::EXPLICIT_ACCESS);
   if (!password_store)
     return;
 
@@ skipping 262 matching lines @@
         break;
       case LIBSECRET:
         usage = OTHER_LIBSECRET;
         break;
     }
   }
   UMA_HISTOGRAM_ENUMERATION("PasswordManager.LinuxBackendStatistics", usage,
                             MAX_BACKEND_USAGE_VALUE);
 }
 #endif