Move Singleton and related structs to namespace base

chrome/browser/custom_handlers/protocol_handler_registry_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/custom_handlers/protocol_handler_registry_factory.h"
 
 #include "base/memory/singleton.h"
 #include "chrome/browser/custom_handlers/protocol_handler_registry.h"
 #include "chrome/browser/profiles/incognito_helpers.h"
 #include "components/keyed_service/content/browser_context_dependency_manager.h"
 
 // static
 ProtocolHandlerRegistryFactory* ProtocolHandlerRegistryFactory::GetInstance() {
-  return Singleton<ProtocolHandlerRegistryFactory>::get();
+  return base::Singleton<ProtocolHandlerRegistryFactory>::get();
 }
 
 // static
 ProtocolHandlerRegistry* ProtocolHandlerRegistryFactory::GetForBrowserContext(
     content::BrowserContext* context) {
   return static_cast<ProtocolHandlerRegistry*>(
       GetInstance()->GetServiceForBrowserContext(context, true));
 }
 
 ProtocolHandlerRegistryFactory::ProtocolHandlerRegistryFactory()
@@ skipping 35 matching lines @@
   // If installing defaults, they must be installed prior calling
   // InitProtocolSettings
   registry->InstallDefaultsForChromeOS();
 #endif
 
   // Must be called as a part of the creation process.
   registry->InitProtocolSettings();
 
   return registry;
 }