Unload the ScopedGaiaAuthExtension asynchronously.

chrome/browser/extensions/signin/scoped_gaia_auth_extension.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/extensions/signin/scoped_gaia_auth_extension.h"
 
 #include "chrome/browser/extensions/signin/gaia_auth_extension_loader.h"
 #include "content/public/browser/browser_context.h"
 
 ScopedGaiaAuthExtension::ScopedGaiaAuthExtension(
     content::BrowserContext* context)
     : browser_context_(context) {
   extensions::GaiaAuthExtensionLoader* loader =
       extensions::GaiaAuthExtensionLoader::Get(browser_context_);
   if (loader)
     loader->LoadIfNeeded();
 }
 
 ScopedGaiaAuthExtension::~ScopedGaiaAuthExtension() {
   extensions::GaiaAuthExtensionLoader* loader =
       extensions::GaiaAuthExtensionLoader::Get(browser_context_);
   if (loader)
-    loader->UnloadIfNeeded();
+    loader->UnloadIfNeededAsync();
 }