app_list: OnExtensionLoaded calls UpdateResults asynchronously rather than directly.

chrome/browser/ui/app_list/search/app_search_provider.h

 // 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.
 
 #ifndef CHROME_BROWSER_UI_APP_LIST_SEARCH_APP_SEARCH_PROVIDER_H_
 #define CHROME_BROWSER_UI_APP_LIST_SEARCH_APP_SEARCH_PROVIDER_H_
 
 #include "base/basictypes.h"
 #include "base/memory/scoped_vector.h"
+#include "base/memory/weak_ptr.h"
 #include "base/scoped_observer.h"
 #include "extensions/browser/extension_registry_observer.h"
 #include "ui/app_list/search_provider.h"
 
 class AppListControllerDelegate;
 class Profile;
 
 namespace base {
 class Clock;
 }
@@ skipping 43 matching lines @@
 
   base::string16 query_;
 
   ScopedObserver<extensions::ExtensionRegistry,
                  extensions::ExtensionRegistryObserver>
       extension_registry_observer_;
 
   Apps apps_;
 
   scoped_ptr<base::Clock> clock_;
+  base::WeakPtrFactory<AppSearchProvider> update_results_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(AppSearchProvider);
 };
 
 }  // namespace app_list
 
 #endif  // CHROME_BROWSER_UI_APP_LIST_SEARCH_APP_SEARCH_PROVIDER_H_