Move Singleton and related structs to namespace base

chrome/browser/autocomplete/shortcuts_backend_factory.h

 // 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.
 
 #ifndef CHROME_BROWSER_AUTOCOMPLETE_SHORTCUTS_BACKEND_FACTORY_H_
 #define CHROME_BROWSER_AUTOCOMPLETE_SHORTCUTS_BACKEND_FACTORY_H_
 
 #include "base/memory/ref_counted.h"
 #include "base/memory/singleton.h"
 #include "components/keyed_service/content/refcounted_browser_context_keyed_service_factory.h"
@@ skipping 17 matching lines @@
   // Creates and returns a backend for testing purposes.
   static scoped_refptr<RefcountedKeyedService> BuildProfileForTesting(
       content::BrowserContext* profile);
 
   // Creates and returns a backend but without creating its persistent database
   // for testing purposes.
   static scoped_refptr<RefcountedKeyedService> BuildProfileNoDatabaseForTesting(
       content::BrowserContext* profile);
 
  private:
-  friend struct DefaultSingletonTraits<ShortcutsBackendFactory>;
+  friend struct base::DefaultSingletonTraits<ShortcutsBackendFactory>;
 
   ShortcutsBackendFactory();
   ~ShortcutsBackendFactory() override;
 
   // BrowserContextKeyedServiceFactory:
   scoped_refptr<RefcountedKeyedService> BuildServiceInstanceFor(
       content::BrowserContext* profile) const override;
   bool ServiceIsNULLWhileTesting() const override;
   void BrowserContextShutdown(content::BrowserContext* context) override;
 
   static scoped_refptr<ShortcutsBackend> CreateShortcutsBackend(
       Profile* profile,
       bool suppress_db);
 };
 
 #endif  // CHROME_BROWSER_AUTOCOMPLETE_SHORTCUTS_BACKEND_FACTORY_H_