Introduce App Launcher for Windows.

chrome/browser/ui/app_list/apps_model_builder.cc

 // Copyright (c) 2012 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/apps_model_builder.h"
 
 #include "base/i18n/case_conversion.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/extensions/extension_service.h"
@@ skipping 136 matching lines @@
 
   bool is_guest_session = Profile::IsGuestSession();
   ExtensionService* service = profile_->GetExtensionService();
   DCHECK(service);
   for (size_t i = 0; i < arraysize(kSpecialApps); ++i) {
     const std::string extension_id(kSpecialApps[i]);
     if (is_guest_session && extension_id == extension_misc::kWebStoreAppId)
       continue;
 
     const Extension* extension = service->GetInstalledExtension(extension_id);
-    DCHECK(extension);
+    if (!extension)
+      continue;
 
     model_->Add(new ExtensionAppItem(profile_, extension, controller_));
   }
 
   special_apps_count_ = model_->item_count();
 }
 
 int AppsModelBuilder::FindApp(const std::string& app_id) {
   DCHECK(model_);
   for (size_t i = special_apps_count_; i < model_->item_count(); ++i) {
@@ skipping 51 matching lines @@
     }
     case chrome::NOTIFICATION_APP_INSTALLED_TO_APPLIST: {
       highlight_app_id_ = *content::Details<const std::string>(details).ptr();
       HighlightApp();
       break;
     }
     default:
       NOTREACHED();
   }
 }