Fix ExtensionServiceTest.ClearExtensionData flakiness

chrome/browser/ui/webui/ntp/app_launcher_handler.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/webui/ntp/app_launcher_handler.h"
 
 #include <vector>
 
 #include "apps/metrics_names.h"
 #include "base/auto_reset.h"
@@ skipping 775 matching lines @@
   // The extension can be uninstalled in another window while the UI was
   // showing. Do nothing in that case.
   const Extension* extension =
       extension_service_->GetInstalledExtension(extension_id_prompting_);
   if (!extension)
     return;
 
   extension_service_->UninstallExtension(
       extension_id_prompting_,
       extensions::UNINSTALL_REASON_USER_INITIATED,
+      base::Bind(&base::DoNothing),
       NULL);
   CleanupAfterUninstall();
 }
 
 void AppLauncherHandler::ExtensionUninstallCanceled() {
   CleanupAfterUninstall();
 }
 
 void AppLauncherHandler::ExtensionEnableFlowFinished() {
   DCHECK_EQ(extension_id_prompting_, extension_enable_flow_->extension_id());
@@ skipping 32 matching lines @@
     Browser* browser = chrome::FindBrowserWithWebContents(
         web_ui()->GetWebContents());
     extension_uninstall_dialog_.reset(
         extensions::ExtensionUninstallDialog::Create(
             extension_service_->profile(),
             browser->window()->GetNativeWindow(),
             this));
   }
   return extension_uninstall_dialog_.get();
 }