Add versioning to PluginFinder metadata.

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 23 matching lines @@
 class PluginFinder {
  public:
   static void RegisterPrefs(PrefServiceSimple* local_state);
 
   static PluginFinder* GetInstance();
 
   // It should be called on the UI thread.
   void Init();
 
 #if defined(ENABLE_PLUGIN_INSTALLATION)
-  void ReinitializePlugins(const base::DictionaryValue& json_metadata);
+  void ReinitializePlugins(scoped_ptr<base::DictionaryValue> json_metadata);
 
   // Finds a plug-in for the given MIME type and language (specified as an IETF
   // language tag, i.e. en-US). If found, sets |installer| to the
   // corresponding PluginInstaller and |plugin_metadata| to a copy of the
   // corresponding PluginMetadata.
   bool FindPlugin(const std::string& mime_type,
                   const std::string& language,
                   PluginInstaller** installer,
                   scoped_ptr<PluginMetadata>* plugin_metadata);
 
@@ skipping 20 matching lines @@
 
   PluginFinder();
   ~PluginFinder();
 
   static base::DictionaryValue* ComputePluginList();
 
   // Loads the plug-in information from the browser resources and parses it.
   // Returns NULL if the plug-in list couldn't be parsed.
   static base::DictionaryValue* LoadPluginList();
 
-  void InitInternal();
+  void InitInternal(scoped_ptr<base::DictionaryValue> plugin_list);
 
   scoped_ptr<base::DictionaryValue> plugin_list_;
 #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_