Add garbage collection for shared extensions on Chrome OS

chrome/browser/extensions/extension_garbage_collector.h

Index: chrome/browser/extensions/extension_garbage_collector.h
diff --git a/chrome/browser/extensions/extension_garbage_collector.h b/chrome/browser/extensions/extension_garbage_collector.h
index 7a9b048b796439cff28b805591be9fc6f9bbcf38..c0805ca9eddfbbfa3bc51c1099cbb8081645599a 100644
--- a/chrome/browser/extensions/extension_garbage_collector.h
+++ b/chrome/browser/extensions/extension_garbage_collector.h
@@ -31,12 +31,6 @@ class ExtensionGarbageCollector : public KeyedService, public InstallObserver {
 
   static ExtensionGarbageCollector* Get(content::BrowserContext* context);
 
-#if defined(OS_CHROMEOS)
-  // Enable or disable garbage collection. See |disable_garbage_collection_|.
-  void disable_garbage_collection() { disable_garbage_collection_ = true; }
-  void enable_garbage_collection() { disable_garbage_collection_ = false; }
-#endif
-
   // Manually trigger GarbageCollectExtensions() for testing.
   void GarbageCollectExtensionsForTest();
 
@@ -48,7 +42,7 @@ class ExtensionGarbageCollector : public KeyedService, public InstallObserver {
   virtual void OnFinishCrxInstall(const std::string& extension_id,
                                   bool success) OVERRIDE;
 
- private:
+ protected:
   // Cleans up the extension install directory. It can end up with garbage in it
   // if extensions can't initially be removed when they are uninstalled (eg if a
   // file is in use).
@@ -56,24 +50,20 @@ class ExtensionGarbageCollector : public KeyedService, public InstallObserver {
   // found in the ExtensionPrefs.
   // The "Temp" directory that is used during extension installation will get
   // removed iff there are no pending installations.
-  void GarbageCollectExtensions();
+  virtual void GarbageCollectExtensions();
 
   // Garbage collects apps/extensions isolated storage if it is uninstalled.
   // There is an exception for ephemeral apps because they can outlive their
   // cache lifetimes.
   void GarbageCollectIsolatedStorageIfNeeded();
 
+  static void GarbageCollectExtensionsOnFileThread(
+      const base::FilePath& install_directory,
+      const std::multimap<std::string, base::FilePath>& extension_paths);
+
   // The BrowserContext associated with the GarbageCollector.
   content::BrowserContext* context_;
 
-#if defined(OS_CHROMEOS)
-  // TODO(rkc): HACK alert - this is only in place to allow the
-  // kiosk_mode_screensaver to prevent its extension from getting garbage
-  // collected. Remove this once KioskModeScreensaver is removed.
-  // See crbug.com/280363
-  bool disable_garbage_collection_;
-#endif
-
   // The number of currently ongoing CRX installations. This is used to prevent
   // garbage collection from running while a CRX is being installed.
   int crx_installs_in_progress_;