Add an API for hosted apps to check their install and running states.

chrome/browser/extensions/extension_service.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_EXTENSIONS_EXTENSION_SERVICE_H_
 #define CHROME_BROWSER_EXTENSIONS_EXTENSION_SERVICE_H_
 #pragma once
 
 #include <list>
 #include <map>
@@ skipping 692 matching lines @@
   // The ExtensionSystem for the profile above.
   ExtensionSystem* system_;
 
   // Preferences for the owning profile (weak reference).
   ExtensionPrefs* extension_prefs_;
 
   // Settings for the owning profile.
   scoped_ptr<extensions::SettingsFrontend> settings_frontend_;
 
   // The current list of installed extensions.
-  // TODO(aa): This should use chrome/common/extensions/extension_set.h.
   ExtensionSet extensions_;
 
   // The list of installed extensions that have been disabled.
   ExtensionSet disabled_extensions_;
 
   // The list of installed extensions that have been terminated.
   ExtensionSet terminated_extensions_;
 
   // Hold the set of pending extensions.
   PendingExtensionManager pending_extension_manager_;
@@ skipping 120 matching lines @@
   scoped_ptr<ExtensionGlobalError> extension_global_error_;
 
   FRIEND_TEST_ALL_PREFIXES(ExtensionServiceTest,
                            InstallAppsWithUnlimtedStorage);
   FRIEND_TEST_ALL_PREFIXES(ExtensionServiceTest,
                            InstallAppsAndCheckStorageProtection);
   DISALLOW_COPY_AND_ASSIGN(ExtensionService);
 };
 
 #endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_SERVICE_H_