Add garbage collection for shared extensions on Chrome OS

chrome/browser/extensions/extension_garbage_collector_chromeos.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_CHROMEOS_H_
+#define CHROME_BROWSER_EXTENSIONS_EXTENSION_GARBAGE_COLLECTOR_CHROMEOS_H_
+
+#include "chrome/browser/extensions/extension_garbage_collector.h"
+
+namespace extensions {
+
+// Chrome OS specific extensions garbage collector. In addition to base class
+// it also cleans up extensions install directory in shared location, see
+// ExtensionAssetsManagerChromeOS.
+class ExtensionGarbageCollectorChromeOS : public ExtensionGarbageCollector {
+ public:
+  explicit ExtensionGarbageCollectorChromeOS(content::BrowserContext* context);
+  virtual ~ExtensionGarbageCollectorChromeOS();
+
+  static ExtensionGarbageCollectorChromeOS* Get(
+      content::BrowserContext* context);
+
+  // 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; }
+
+ private:
+  // Overriddes for ExtensionGarbageCollector:
+  virtual void GarbageCollectExtensions() OVERRIDE;
+
+  // Return true if there is no extension installation for all active profiles.
+  bool CanGarbageCollectSharedExtensions();
+
+  // Do GC for shared extensions dir.
+  void GarbageCollectSharedExtensions();
+
+  // 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_;
+
+  // Shared extensions need to be processed only once but instances of this
+  // class are created per-profile so this static variable prevents multiple
+  // processing.
+  static bool shared_extensions_garbage_collected;
+
+  DISALLOW_COPY_AND_ASSIGN(ExtensionGarbageCollectorChromeOS);
+};
+
+}  // namespace extensions
+
+#endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_GARBAGE_COLLECTOR_CHROMEOS_H_