Fix ExtensionServiceTest.ClearExtensionData flakiness

chrome/browser/apps/ephemeral_app_browsertest.cc

 // Copyright 2014 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/apps/ephemeral_app_browsertest.h"
 
 #include <vector>
 
 #include "apps/saved_files_service.h"
 #include "base/files/scoped_temp_dir.h"
@@ skipping 227 matching lines @@
   // Uninstall the app, which is what happens when ephemeral apps get evicted
   // from the cache.
   content::WindowedNotificationObserver uninstalled_signal(
       chrome::NOTIFICATION_EXTENSION_UNINSTALLED_DEPRECATED,
       content::Source<Profile>(profile()));
 
   ExtensionService* service =
       ExtensionSystem::Get(profile())->extension_service();
   ASSERT_TRUE(service);
   service->UninstallExtension(
-      app_id, extensions::UNINSTALL_REASON_ORPHANED_EPHEMERAL_EXTENSION, NULL);
+      app_id,
+      extensions::UNINSTALL_REASON_ORPHANED_EPHEMERAL_EXTENSION,
+      base::Bind(&base::DoNothing),
+      NULL);
 
   uninstalled_signal.Wait();
 }
 
 // EphemeralAppBrowserTest:
 
 class EphemeralAppBrowserTest : public EphemeralAppTestBase {
  protected:
   bool LaunchAppAndRunTest(const Extension* app, const char* test_name) {
     ExtensionTestMessageListener launched_listener("launched", true);
@@ skipping 465 matching lines @@
 
   // Ensure that when the app is promoted to an installed app, the bit in the
   // creation flags is cleared.
   PromoteEphemeralApp(app);
   EXPECT_FALSE(extensions::util::IsEphemeralApp(app->id(), profile()));
 
   int creation_flags =
       ExtensionPrefs::Get(profile())->GetCreationFlags(app->id());
   EXPECT_EQ(0, creation_flags & Extension::IS_EPHEMERAL);
 }