Install and launch kiosk app from cached crx file at start up.

chrome/browser/chromeos/app_mode/kiosk_app_manager_observer.h

Index: chrome/browser/chromeos/app_mode/kiosk_app_manager_observer.h
diff --git a/chrome/browser/chromeos/app_mode/kiosk_app_manager_observer.h b/chrome/browser/chromeos/app_mode/kiosk_app_manager_observer.h
index fc6369e608a89c2d3b5ce9f566d7fc5e4853369f..00eec8c9d92b87252a4d848d2fd72e1373c21ba1 100644
--- a/chrome/browser/chromeos/app_mode/kiosk_app_manager_observer.h
+++ b/chrome/browser/chromeos/app_mode/kiosk_app_manager_observer.h
@@ -17,6 +17,12 @@ class KioskAppManagerObserver {
   // Invoked when failed to load web store data of an app.
   virtual void OnKioskAppDataLoadFailure(const std::string& app_id) {}
 
+  // Invoked when the extension is loaded in cache.
+  virtual void OnKioskExtensionLoadedInCache(const std::string& app_id) {}
+
+  // Invoked when the extension download fails.
+  virtual void OnKioskExtensionDownloadFailed(const std::string& app_id) {}
+
   // Invoked when the Kiosk Apps configuration changes.
   virtual void OnKioskAppsSettingsChanged() {}