Ensure tests have an active task runner

chrome/browser/supervised_user/legacy/supervised_user_pref_mapping_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 <string>
 
 #include "base/prefs/pref_service.h"
 #include "chrome/browser/supervised_user/legacy/supervised_user_pref_mapping_service.h"
 #include "chrome/browser/supervised_user/legacy/supervised_user_pref_mapping_service_factory.h"
 #include "chrome/browser/supervised_user/legacy/supervised_user_shared_settings_service.h"
 #include "chrome/browser/supervised_user/legacy/supervised_user_shared_settings_service_factory.h"
 #include "chrome/browser/supervised_user/supervised_user_constants.h"
 #include "chrome/common/pref_names.h"
 #include "chrome/test/base/testing_profile.h"
+#include "content/public/test/test_browser_thread_bundle.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 const char kFakeSupervisedUserId[] = "fakeID";
 
 class SupervisedUserPrefMappingServiceTest : public ::testing::Test {
  protected:
   SupervisedUserPrefMappingServiceTest() {
     profile_.GetPrefs()->SetString(prefs::kSupervisedUserId,
                                    kFakeSupervisedUserId);
     shared_settings_service_ =
         SupervisedUserSharedSettingsServiceFactory::GetForBrowserContext(
             &profile_);
     mapping_service_ =
         SupervisedUserPrefMappingServiceFactory::GetForBrowserContext(
             &profile_);
   }
   ~SupervisedUserPrefMappingServiceTest() override {}
 
   // testing::Test overrides:
   void SetUp() override { mapping_service_->Init(); }
 
   void TearDown() override {
     mapping_service_->Shutdown();
     shared_settings_service_->Shutdown();
   }
 
+  content::TestBrowserThreadBundle thread_bundle_;
   TestingProfile profile_;
   SupervisedUserSharedSettingsService* shared_settings_service_;
   SupervisedUserPrefMappingService* mapping_service_;
 };
 
 TEST_F(SupervisedUserPrefMappingServiceTest, CheckPrefUpdate) {
   EXPECT_TRUE(shared_settings_service_->GetValue(
                   kFakeSupervisedUserId,
                   supervised_users::kChromeAvatarIndex) == NULL);
   profile_.GetPrefs()->SetInteger(prefs::kProfileAvatarIndex, 4);
   const base::Value* value = shared_settings_service_->GetValue(
       kFakeSupervisedUserId, supervised_users::kChromeAvatarIndex);
   int avatar_index;
   value->GetAsInteger(&avatar_index);
   EXPECT_EQ(avatar_index, 4);
 }
 
 TEST_F(SupervisedUserPrefMappingServiceTest, CheckSharedSettingUpdate) {
   EXPECT_EQ(profile_.GetPrefs()->GetInteger(prefs::kProfileAvatarIndex), -1);
   shared_settings_service_->SetValue(kFakeSupervisedUserId,
                                      supervised_users::kChromeAvatarIndex,
                                      base::FundamentalValue(1));
   mapping_service_->OnSharedSettingChanged(
       kFakeSupervisedUserId,
       supervised_users::kChromeAvatarIndex);
   EXPECT_EQ(profile_.GetPrefs()->GetInteger(prefs::kProfileAvatarIndex), 1);
 }