Download and cache kiosk app extension when it is added via kiosk mamangement ui.

chrome/browser/chromeos/app_mode/kiosk_app_data_delegate.h

 // Copyright 2013 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_CHROMEOS_APP_MODE_KIOSK_APP_DATA_DELEGATE_H_
 #define CHROME_BROWSER_CHROMEOS_APP_MODE_KIOSK_APP_DATA_DELEGATE_H_
 
 #include <string>
 
 namespace base {
 class FilePath;
 }
 
 namespace chromeos {
 
 class KioskAppDataDelegate {
  public:
   // Invoked to get the root directory for storing cached icon files.
   virtual void GetKioskAppIconCacheDir(base::FilePath* cache_dir) = 0;
 
+  // Invoked to get the root directory for storing cached crx files.
+  virtual void GetKioskAppCrxCacheDir(base::FilePath* cache_dir) = 0;

[xiyuan, 2014/05/02 22:19:45]

This does not belong here since KioskAppData does not handle crx cache. It
should just be a method in KioskAppManager.

[jennyz, 2014/05/02 22:31:01]

Done.

+
   // Invoked when kiosk app data or status has changed.
   virtual void OnKioskAppDataChanged(const std::string& app_id) = 0;
 
   // Invoked when failed to load web store data of an app.
   virtual void OnKioskAppDataLoadFailure(const std::string& app_id) = 0;
 
  protected:
   virtual ~KioskAppDataDelegate() {}
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_APP_MODE_KIOSK_APP_DATA_DELEGATE_H_