Move Singleton and related structs to namespace base

chrome/browser/extensions/api/passwords_private/passwords_private_delegate_factory.h

 // Copyright 2015 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.
 
 #ifndef CHROME_BROWSER_EXTENSIONS_API_PASSWORDS_PRIVATE_PASSWORDS_PRIVATE_DELEGATE_FACTORY_H_
 #define CHROME_BROWSER_EXTENSIONS_API_PASSWORDS_PRIVATE_PASSWORDS_PRIVATE_DELEGATE_FACTORY_H_
 
 #include "base/memory/singleton.h"
 #include "components/keyed_service/content/browser_context_keyed_service_factory.h"
 
 namespace context {
 class BrowserContext;
 }
 
 namespace extensions {
 class PasswordsPrivateDelegate;
 
 // Factory for creating PasswordPrivateDelegates.
 class PasswordsPrivateDelegateFactory
     : public BrowserContextKeyedServiceFactory {
  public:
   static PasswordsPrivateDelegate* GetForBrowserContext(
       content::BrowserContext* browser_context,
       bool create);
 
   static PasswordsPrivateDelegateFactory* GetInstance();
 
  private:
-  friend struct DefaultSingletonTraits<PasswordsPrivateDelegateFactory>;
+  friend struct base::DefaultSingletonTraits<PasswordsPrivateDelegateFactory>;
 
   PasswordsPrivateDelegateFactory();
   ~PasswordsPrivateDelegateFactory() override;
 
   // BrowserContextKeyedBaseFactory implementation.
   KeyedService* BuildServiceInstanceFor(
       content::BrowserContext* profile) const override;
   bool ServiceIsCreatedWithBrowserContext() const override;
   bool ServiceIsNULLWhileTesting() const override;
 
   DISALLOW_COPY_AND_ASSIGN(PasswordsPrivateDelegateFactory);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_API_PASSWORDS_PRIVATE_PASSWORDS_PRIVATE_DELEGATE_FACTORY_H_