Move Singleton and related structs to namespace base

chrome/browser/net/spdyproxy/data_reduction_proxy_chrome_settings_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 CHROME_BROWSER_NET_SPDYPROXY_DATA_REDUCTION_PROXY_CHROME_SETTINGS_FACTORY_H_
 #define CHROME_BROWSER_NET_SPDYPROXY_DATA_REDUCTION_PROXY_CHROME_SETTINGS_FACTORY_H_
 
 #include "base/compiler_specific.h"
 #include "base/memory/singleton.h"
 #include "components/keyed_service/content/browser_context_keyed_service_factory.h"
@@ skipping 11 matching lines @@
       content::BrowserContext* context);
 
   // Returns true if this context has a settings object.
   static bool HasDataReductionProxyChromeSettings(
       content::BrowserContext* context);
 
   // Returns an instance of this factory.
   static DataReductionProxyChromeSettingsFactory* GetInstance();
 
  private:
-  friend struct DefaultSingletonTraits<DataReductionProxyChromeSettingsFactory>;
+  friend struct base::DefaultSingletonTraits<
+      DataReductionProxyChromeSettingsFactory>;
 
   DataReductionProxyChromeSettingsFactory();
 
   ~DataReductionProxyChromeSettingsFactory() override;
 
   // BrowserContextKeyedServiceFactory:
   KeyedService* BuildServiceInstanceFor(
       content::BrowserContext* context) const override;
 
   DISALLOW_COPY_AND_ASSIGN(DataReductionProxyChromeSettingsFactory);
 };
 
 #endif  // CHROME_BROWSER_NET_SPDYPROXY_DATA_REDUCTION_PROXY_CHROME_SETTINGS_FACTORY_H_