Move Singleton and related structs to namespace base

chrome/browser/autocomplete/autocomplete_classifier_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_AUTOCOMPLETE_CLASSIFIER_FACTORY_H_
 #define CHROME_BROWSER_AUTOCOMPLETE_AUTOCOMPLETE_CLASSIFIER_FACTORY_H_
 
 #include "base/basictypes.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/singleton.h"
 #include "components/keyed_service/content/browser_context_keyed_service_factory.h"
 
 class AutocompleteClassifier;
 class Profile;
 
 // Singleton that owns all AutocompleteClassifiers and associates them with
 // Profiles.
 class AutocompleteClassifierFactory : public BrowserContextKeyedServiceFactory {
  public:
   // Returns the AutocompleteClassifier for |profile|.
   static AutocompleteClassifier* GetForProfile(Profile* profile);
 
   static AutocompleteClassifierFactory* GetInstance();
 
   static scoped_ptr<KeyedService> BuildInstanceFor(
       content::BrowserContext* context);
 
  private:
-  friend struct DefaultSingletonTraits<AutocompleteClassifierFactory>;
+  friend struct base::DefaultSingletonTraits<AutocompleteClassifierFactory>;
 
   AutocompleteClassifierFactory();
   ~AutocompleteClassifierFactory() override;
 
   // BrowserContextKeyedServiceFactory:
   content::BrowserContext* GetBrowserContextToUse(
       content::BrowserContext* context) const override;
   bool ServiceIsNULLWhileTesting() const override;
   KeyedService* BuildServiceInstanceFor(
       content::BrowserContext* profile) const override;
 
   DISALLOW_COPY_AND_ASSIGN(AutocompleteClassifierFactory);
 };
 
 #endif  // CHROME_BROWSER_AUTOCOMPLETE_AUTOCOMPLETE_CLASSIFIER_FACTORY_H_