Move Singleton and related structs to namespace base

chrome/browser/extensions/extension_storage_monitor_factory.cc

 // Copyright 2014 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/extensions/extension_storage_monitor_factory.h"
 
 #include "chrome/browser/extensions/extension_storage_monitor.h"
 #include "chrome/browser/extensions/extension_system_factory.h"
 #include "components/keyed_service/content/browser_context_dependency_manager.h"
 #include "extensions/browser/extension_prefs_factory.h"
 #include "extensions/browser/extensions_browser_client.h"
 
 namespace extensions {
 
 // static
 ExtensionStorageMonitor*
 ExtensionStorageMonitorFactory::GetForBrowserContext(
     content::BrowserContext* context) {
   return static_cast<ExtensionStorageMonitor*>(
       GetInstance()->GetServiceForBrowserContext(context, true));
 }
 
 // static
 ExtensionStorageMonitorFactory* ExtensionStorageMonitorFactory::GetInstance() {
-  return Singleton<ExtensionStorageMonitorFactory>::get();
+  return base::Singleton<ExtensionStorageMonitorFactory>::get();
 }
 
 ExtensionStorageMonitorFactory::ExtensionStorageMonitorFactory()
     : BrowserContextKeyedServiceFactory(
           "ExtensionStorageMonitor",
           BrowserContextDependencyManager::GetInstance()) {
   DependsOn(ExtensionsBrowserClient::Get()->GetExtensionSystemFactory());
   DependsOn(ExtensionPrefsFactory::GetInstance());
 }
 
@@ skipping 13 matching lines @@
 bool ExtensionStorageMonitorFactory::ServiceIsCreatedWithBrowserContext()
     const {
   return true;
 }
 
 bool ExtensionStorageMonitorFactory::ServiceIsNULLWhileTesting() const {
   return true;
 }
 
 }  // namespace extensions