Add garbage collection for shared extensions on Chrome OS

chrome/browser/extensions/extension_assets_manager_chromeos.h

 // Copyright (c) 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_EXTENSIONS_EXTENSION_ASSETS_MANAGER_CHROMEOS_H_
 #define CHROME_BROWSER_EXTENSIONS_EXTENSION_ASSETS_MANAGER_CHROMEOS_H_
 
+#include <map>
+
 #include "chrome/browser/extensions/extension_assets_manager.h"
 
 template <typename T> struct DefaultSingletonTraits;
 class PrefRegistrySimple;
 
 namespace base {
+class DictionaryValue;
 class SequencedTaskRunner;
 }
 
 namespace extensions {
 
 // Chrome OS specific implementation of assets manager that shares default apps
 // between all users on the machine.
 class ExtensionAssetsManagerChromeOS : public ExtensionAssetsManager {
  public:
   static ExtensionAssetsManagerChromeOS* GetInstance();
 
-  // Path to shared extensions install dir.
-  static const char kSharedExtensionsDir[];
+  // A dictionary that maps shared extension IDs to version/paths/users.
+  static const char kSharedExtensions[];
+
+  // Name of path attribute in shared extensions map.
+  static const char kSharedExtensionPath[];
+
+  // Name of users attribute (list of user emails) in shared extensions map.
+  static const char kSharedExtensionUsers[];
 
   // Register shared assets related preferences.
   static void RegisterPrefs(PrefRegistrySimple* registry);
 
   // Override from ExtensionAssetsManager.
   virtual void InstallExtension(const Extension* extension,
                                 const base::FilePath& unpacked_extension_root,
                                 const base::FilePath& local_install_dir,
                                 Profile* profile,
                                 InstallExtensionCallback callback) OVERRIDE;
   virtual void UninstallExtension(
       const std::string& id,
       Profile* profile,
       const base::FilePath& local_install_dir,
       const base::FilePath& extension_root) OVERRIDE;
 
+  // Return shared install dir.
+  static base::FilePath GetSharedInstallDir();
+
+  // Cleans up shared extensions list in preferences and returns list of
+  // extension IDs and version paths that are in use in |live_extension_paths|.
+  // Files on disk are not removed. Must be called on UI thread.
+  // Returns |false| in case of errors.
+  static bool CleanUpSharedExtensions(
+      std::multimap<std::string, base::FilePath>* live_extension_paths);
+
   static void SetSharedInstallDirForTesting(const base::FilePath& install_dir);
 
  private:
   friend struct DefaultSingletonTraits<ExtensionAssetsManagerChromeOS>;
 
   ExtensionAssetsManagerChromeOS();
   virtual ~ExtensionAssetsManagerChromeOS();
 
   // Should be called on UI thread to get associated file task runner for
   // the profile.
   static base::SequencedTaskRunner* GetFileTaskRunner(Profile* profile);
 
-  // Return shared install dir.
-  static base::FilePath GetSharedInstallDir();
-
   // Return |true| if |extension| can be installed in a shared place for all
   // users on the device.
   static bool CanShareAssets(const Extension* extension);
 
   // Called on the UI thread to check if a given version of the |extension|
   // already exists at the shared location.
   static void CheckSharedExtension(
       const std::string& id,
       const std::string& version,
       const base::FilePath& unpacked_extension_root,
@@ skipping 22 matching lines @@
       const base::FilePath& local_install_dir,
       InstallExtensionCallback callback);
 
   // Called on UI thread to mark that shared version is not used.
   static void MarkSharedExtensionUnused(const std::string& id,
                                         Profile* profile);
 
   // Called on task runner thread to remove shared version.
   static void DeleteSharedVersion(const base::FilePath& shared_version_dir);
 
+  // Clean shared extension with given |id|.
+  static bool CleanUpExtension(
+      const std::string& id,
+      base::DictionaryValue* extension_info,
+      std::multimap<std::string, base::FilePath>* live_extension_paths);
+
   DISALLOW_COPY_AND_ASSIGN(ExtensionAssetsManagerChromeOS);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_ASSETS_MANAGER_CHROMEOS_H_