Call InstallTracker::RemoveObserver when StartupAppLauncher is destroyed

chrome/browser/chromeos/app_mode/startup_app_launcher.cc

 // 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.
 
 #include "chrome/browser/chromeos/app_mode/startup_app_launcher.h"
 
 #include "base/command_line.h"
 #include "base/files/file_path.h"
 #include "base/json/json_file_value_serializer.h"
 #include "base/path_service.h"
@@ skipping 72 matching lines @@
   KioskAppManager::Get()->AddObserver(this);
 }
 
 StartupAppLauncher::~StartupAppLauncher() {
   KioskAppManager::Get()->RemoveObserver(this);
 
   // StartupAppLauncher can be deleted at anytime during the launch process
   // through a user bailout shortcut.
   ProfileOAuth2TokenServiceFactory::GetForProfile(profile_)
       ->RemoveObserver(this);
+  extensions::InstallTrackerFactory::GetForBrowserContext(profile_)
+      ->RemoveObserver(this);
 }
 
 void StartupAppLauncher::Initialize() {
   StartLoadingOAuthFile();
 }
 
 void StartupAppLauncher::ContinueWithNetworkReady() {
   if (!network_ready_handled_) {
     network_ready_handled_ = true;
     // The network might not be ready when KioskAppManager tries to update
@@ skipping 292 matching lines @@
   UpdateAppData();
   delegate_->OnReadyToLaunch();
 }
 
 void StartupAppLauncher::UpdateAppData() {
   KioskAppManager::Get()->ClearAppData(app_id_);
   KioskAppManager::Get()->UpdateAppDataFromProfile(app_id_, profile_, NULL);
 }
 
 }   // namespace chromeos