arc: Fix crash on deferred app launch.

chrome/browser/ui/ash/launcher/arc_app_deferred_launcher_controller.cc

 // Copyright 2016 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/ui/ash/launcher/arc_app_deferred_launcher_controller.h"
 
 #include "base/threading/thread_task_runner_handle.h"
 #include "chrome/browser/chromeos/arc/arc_util.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/app_list/arc/arc_app_utils.h"
@@ skipping 180 matching lines @@
   DCHECK(arc_session_manager->state() !=
          arc::ArcSessionManager::State::STOPPED);
   DCHECK(arc_session_manager->state() !=
          arc::ArcSessionManager::State::NOT_INITIALIZED);
 
   const std::string shelf_app_id =
       ArcAppWindowLauncherController::GetShelfAppIdFromArcAppId(app_id);
   const ash::ShelfID shelf_id = owner_->GetShelfIDForAppID(shelf_app_id);
 
   // We are allowed to apply new deferred controller only over shortcut.
-  const ash::ShelfItem* item = owner_->GetItem(shelf_id);
-  if (item && item->type != ash::TYPE_APP_SHORTCUT)
+  const LauncherItemController* existing_controller =
+      owner_->GetLauncherItemController(shelf_id);
+  if (existing_controller && !existing_controller->IsShortcut())

[msw, 2017/03/14 01:24:59]

Can you write an automated test that ensures this doesn't crash/regress?

[khmel, 2017/03/14 20:19:56]

Done.

     return;
 
   ArcAppDeferredLauncherItemController* controller =
       new ArcAppDeferredLauncherItemController(
           shelf_app_id, owner_, event_flags, weak_ptr_factory_.GetWeakPtr());
   if (shelf_id == 0) {
     owner_->CreateAppLauncherItem(controller, shelf_app_id,
                                   ash::STATUS_RUNNING);
   } else {
     owner_->SetItemController(shelf_id, controller);
     owner_->SetItemStatus(shelf_id, ash::STATUS_RUNNING);
   }
 
   if (app_controller_map_.empty())
     RegisterNextUpdate();
 
   app_controller_map_[shelf_app_id] = controller;
 }