Require explicit selection of traits for LazyInstance

chrome/browser/previews/previews_service_factory.h

 // Copyright 2016 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_PREVIEWS_PREVIEWS_SERVICE_FACTORY_H_
 #define CHROME_BROWSER_PREVIEWS_PREVIEWS_SERVICE_FACTORY_H_
 
 #include "base/lazy_instance.h"
 #include "base/macros.h"
 #include "components/keyed_service/content/browser_context_keyed_service_factory.h"
 
 namespace content {
 class BrowserContext;
 }
 
 class PreviewsService;
 class Profile;
 
 // LazyInstance that owns all PreviewsServices and associates them with
 // Profiles.
 class PreviewsServiceFactory : public BrowserContextKeyedServiceFactory {
  public:
   // Gets the PreviewsService instance for |profile|.
   static PreviewsService* GetForProfile(Profile* profile);
 
   // Gets the LazyInstance that owns all PreviewsServices.
   static PreviewsServiceFactory* GetInstance();
 
  private:
-  friend struct base::DefaultLazyInstanceTraits<PreviewsServiceFactory>;
+  friend struct base::LazyInstanceTraitsBase<PreviewsServiceFactory>;
 
   PreviewsServiceFactory();
   ~PreviewsServiceFactory() override;
 
   // BrowserContextKeyedServiceFactory:
   KeyedService* BuildServiceInstanceFor(
       content::BrowserContext* context) const override;
 
   DISALLOW_COPY_AND_ASSIGN(PreviewsServiceFactory);
 };
 
 #endif  // CHROME_BROWSER_PREVIEWS_PREVIEWS_SERVICE_FACTORY_H_