Fix several crashes for ARC app launcher.

chrome/browser/ui/app_list/model_pref_updater.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/ui/app_list/model_pref_updater.h"
 
 #include "chrome/browser/ui/app_list/app_list_prefs.h"
 #include "chrome/browser/ui/app_list/extension_app_item.h"
 #include "ui/app_list/app_list_folder_item.h"
 #include "ui/app_list/app_list_item.h"
 #include "ui/app_list/app_list_model.h"
 
+#if defined(OS_CHROMEOS)
+#include "chrome/browser/ui/app_list/arc/arc_app_item.h"
+#endif
+
 namespace app_list {
 
 ModelPrefUpdater::ModelPrefUpdater(AppListPrefs* app_list_prefs,
                                    AppListModel* model)
     : app_list_prefs_(app_list_prefs), model_(model) {
   model_->AddObserver(this);
 }
 
 ModelPrefUpdater::~ModelPrefUpdater() {
   model_->RemoveObserver(this);
@@ skipping 11 matching lines @@
   UpdatePrefsFromAppListItem(item);
 }
 
 void ModelPrefUpdater::UpdatePrefsFromAppListItem(AppListItem* item) {
   // Write synced data to local pref.
   AppListPrefs::AppListInfo info;
   if (item->GetItemType() == AppListFolderItem::kItemType)
     info.item_type = AppListPrefs::AppListInfo::FOLDER_ITEM;
   else if (item->GetItemType() == ExtensionAppItem::kItemType)
     info.item_type = AppListPrefs::AppListInfo::APP_ITEM;
+#if defined(OS_CHROMEOS)
+  else if (item->GetItemType() == ArcAppItem::kItemType)

[khmel, 2015/12/08 05:42:51]

'grep -r "ExtensionAppItem::kItemType" --include=*.cc' shows 2 places where
ExtensionAppItem::kItemType are used without  ArcAppItem::kItemType. One place
is here, second place is here:
https://code.google.com/p/chromium/codesearch#chromium/src/chrome/browser/ui/....


ModelPrefUpdaterTest works with mock item that has extension type only.

So adding new type only here.

+    info.item_type = AppListPrefs::AppListInfo::APP_ITEM;
+#endif
   else
     NOTREACHED();
 
   info.parent_id = item->folder_id();
   info.position = item->position();
   info.name = item->name();
 
   app_list_prefs_->SetAppListInfo(item->id(), info);
 }
 
 }  // namespace app_list