Move Singleton and related structs to namespace base

chrome/browser/plugins/plugin_finder.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_PLUGINS_PLUGIN_FINDER_H_
 #define CHROME_BROWSER_PLUGINS_PLUGIN_FINDER_H_
 
 #include <map>
 #include <string>
 
@@ skipping 56 matching lines @@
   // Returns the plugin name with the given |mime_type| and |language| or
   // |mime_type| if not found.
   base::string16 FindPluginName(const std::string& mime_type,
                                 const std::string& language);
 
   // Gets plugin metadata using |plugin|.
   scoped_ptr<PluginMetadata> GetPluginMetadata(
       const content::WebPluginInfo& plugin);
 
  private:
-  friend struct DefaultSingletonTraits<PluginFinder>;
-  friend class Singleton<PluginFinder>;
+  friend struct base::DefaultSingletonTraits<PluginFinder>;
   FRIEND_TEST_ALL_PREFIXES(PluginFinderTest, JsonSyntax);
   FRIEND_TEST_ALL_PREFIXES(PluginFinderTest, PluginGroups);
 
   PluginFinder();
   ~PluginFinder();
 
   // Loads the plugin information from the browser resources and parses it.
   // Returns NULL if the plugin list couldn't be parsed.
   static base::DictionaryValue* LoadBuiltInPluginList();
 
 #if defined(ENABLE_PLUGIN_INSTALLATION)
   std::map<std::string, PluginInstaller*> installers_;
 #endif
 
   std::map<std::string, PluginMetadata*> identifier_plugin_;
 
   // Version of the metadata information. We use this to consolidate multiple
   // sources (baked into resource and fetched from a URL), making sure that we
   // don't overwrite newer versions with older ones.
   int version_;
 
   // Synchronization for the above member variables is
   // required since multiple threads can be accessing them concurrently.
   base::Lock mutex_;
 
   DISALLOW_COPY_AND_ASSIGN(PluginFinder);
 };
 
 #endif  // CHROME_BROWSER_PLUGINS_PLUGIN_FINDER_H_