Move Singleton and related structs to namespace base

components/devtools_discovery/devtools_discovery_manager.h

 // Copyright 2015 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_DEVTOOLS_DISCOVERY_DEVTOOLS_DISCOVERY_MANAGER_H_
 #define COMPONENTS_DEVTOOLS_DISCOVERY_DEVTOOLS_DISCOVERY_MANAGER_H_
 
 #include <string>
 
 #include "base/memory/scoped_ptr.h"
@@ skipping 20 matching lines @@
   static DevToolsDiscoveryManager* GetInstance();
 
   void AddProvider(scoped_ptr<Provider> provider);
   void SetCreateCallback(const CreateCallback& callback);
 
   // Caller takes ownership of created descriptors.
   DevToolsTargetDescriptor::List GetDescriptors();
   scoped_ptr<DevToolsTargetDescriptor> CreateNew(const GURL& url);
 
  private:
-  friend struct DefaultSingletonTraits<DevToolsDiscoveryManager>;
+  friend struct base::DefaultSingletonTraits<DevToolsDiscoveryManager>;
 
   DevToolsDiscoveryManager();
   ~DevToolsDiscoveryManager();
   DevToolsTargetDescriptor::List GetDescriptorsFromProviders();
 
   std::vector<Provider*> providers_;
   CreateCallback create_callback_;
 
   DISALLOW_COPY_AND_ASSIGN(DevToolsDiscoveryManager);
 };
 
 }  // namespace devtools_discovery
 
 #endif  // COMPONENTS_DEVTOOLS_DISCOVERY_DEVTOOLS_DISCOVERY_MANAGER_H_