Ensure tests have an active task runner

chrome/browser/supervised_user/supervised_user_settings_service_unittest.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 "base/bind.h"
 #include "base/callback.h"
 #include "base/json/json_reader.h"
 #include "base/prefs/testing_pref_store.h"
 #include "base/strings/string_util.h"
 #include "chrome/browser/supervised_user/supervised_user_settings_service.h"
+#include "content/public/test/test_browser_thread_bundle.h"
 #include "sync/api/fake_sync_change_processor.h"
 #include "sync/api/sync_change.h"
 #include "sync/api/sync_change_processor_wrapper_for_test.h"
 #include "sync/api/sync_error_factory_mock.h"
 #include "sync/protocol/sync.pb.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace {
 
 class MockSyncErrorFactory : public syncer::SyncErrorFactory {
@@ skipping 105 matching lines @@
         base::Bind(&SupervisedUserSettingsServiceTest::OnNewSettingsAvailable,
                    base::Unretained(this)));
     pref_store->SetInitializationCompleted();
     ASSERT_FALSE(settings_);
     settings_service_.SetActive(true);
     ASSERT_TRUE(settings_);
   }
 
   void TearDown() override { settings_service_.Shutdown(); }
 
+  content::TestBrowserThreadBundle thread_bundle_;
   base::DictionaryValue split_items_;
   scoped_ptr<base::Value> atomic_setting_value_;
   SupervisedUserSettingsService settings_service_;
   scoped_ptr<base::DictionaryValue> settings_;
 
   scoped_ptr<syncer::FakeSyncChangeProcessor> sync_processor_;
 };
 
 TEST_F(SupervisedUserSettingsServiceTest, ProcessAtomicSetting) {
   StartSyncing(syncer::SyncDataList());
@@ skipping 134 matching lines @@
   // The uploaded items should not show up as settings.
   const base::Value* value = NULL;
   EXPECT_FALSE(settings_->GetWithoutPathExpansion(kAtomicItemName, &value));
   EXPECT_FALSE(settings_->GetWithoutPathExpansion(kSplitItemName, &value));
 
   // Restarting sync should not create any new changes.
   settings_service_.StopSyncing(syncer::SUPERVISED_USER_SETTINGS);
   StartSyncing(sync_data);
   ASSERT_EQ(0u, sync_processor_->changes().size());
 }