Unload the ScopedGaiaAuthExtension asynchronously.

chrome/browser/ui/cocoa/bookmarks/bookmark_sync_promo_controller_unittest.mm

 // 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.
 
 #import "chrome/browser/ui/cocoa/bookmarks/bookmark_sync_promo_controller.h"
 
 #import <Cocoa/Cocoa.h>
 
 #include "base/basictypes.h"
 #include "base/command_line.h"
@@ skipping 25 matching lines @@
 
   base::scoped_nsobject<BookmarkSyncPromoController> syncPromo(
       [[BookmarkSyncPromoController alloc] initWithBrowser:browser()]);
 
   // Simulate clicking the "Sign in" link.
   [syncPromo textView:nil clickedOnLink:nil atIndex:0u];
 
   // A new tab should have been opened.
   int tab_count = browser()->tab_strip_model()->count();
   EXPECT_EQ(starting_tab_count + 1, tab_count);
+
+  // Close the tab, so that the gaia auth extension is unloaded correctly.
+  // Otherwise the test can crash if the profile is deleted before the extension
+  // is unloaded.
+  browser()->tab_strip_model()->CloseAllTabs();
 }
 
 }  // namespace