Move Singleton and related structs to namespace base

components/feedback/feedback_uploader_factory.h

 // Copyright 2014 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 COMPONENTS_FEEDBACK_FEEDBACK_UPLOADER_FACTORY_H_
 #define COMPONENTS_FEEDBACK_FEEDBACK_UPLOADER_FACTORY_H_
 
 #include "components/keyed_service/content/browser_context_keyed_service_factory.h"
 
+namespace base {
 template<typename T> struct DefaultSingletonTraits;
+}
 
 namespace content {
 class BrowserContext;
 }
 
 namespace feedback {
 
 class FeedbackUploader;
 
 // Singleton that owns the FeedbackUploaders and associates them with profiles;
 class FeedbackUploaderFactory : public BrowserContextKeyedServiceFactory {
  public:
   // Returns singleton instance of FeedbackUploaderFactory.
   static FeedbackUploaderFactory* GetInstance();
 
   // Returns the Feedback Uploader associated with |context|.
   static FeedbackUploader* GetForBrowserContext(
       content::BrowserContext* context);
 
  private:
-  friend struct DefaultSingletonTraits<FeedbackUploaderFactory>;
+  friend struct base::DefaultSingletonTraits<FeedbackUploaderFactory>;
 
   FeedbackUploaderFactory();
   ~FeedbackUploaderFactory() override;
 
   // BrowserContextKeyedServiceFactory overrides:
   KeyedService* BuildServiceInstanceFor(
       content::BrowserContext* context) const override;
   content::BrowserContext* GetBrowserContextToUse(
       content::BrowserContext* context) const override;
 
   DISALLOW_COPY_AND_ASSIGN(FeedbackUploaderFactory);
 };
 
 }  // namespace feedback
 
 #endif  // COMPONENTS_FEEDBACK_FEEDBACK_UPLOADER_FACTORY_H_