[Extension] Protect all installed extension from extension storage GC

chrome/browser/extensions/extension_garbage_collector.h

 // Copyright 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_GARBAGE_COLLECTOR_H_
 #define CHROME_BROWSER_EXTENSIONS_EXTENSION_GARBAGE_COLLECTOR_H_
 
 #include <map>
 #include <string>
 
@@ skipping 42 matching lines @@
  private:
   // 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).
   // Obsolete version directories are removed, as are directories that aren't
   // found in the ExtensionPrefs.
   // The "Temp" directory that is used during extension installation will get
   // removed iff there are no pending installations.
   void GarbageCollectExtensions();
 
-  // Garbage collects apps/extensions isolated storage, if it is not currently
-  // active (i.e. is not in ExtensionRegistry::ENABLED). There is an exception
-  // for ephemeral apps, because they can outlive their cache lifetimes.
+  // 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();
 
   // 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_;
 
   // Generate weak pointers for safely posting to the file thread for garbage
   // collection.
   base::WeakPtrFactory<ExtensionGarbageCollector> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ExtensionGarbageCollector);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_GARBAGE_COLLECTOR_H_