Use a TestBrowserThreadBundle in the DeviceSettingsTestBase.

chrome/browser/chromeos/settings/device_settings_test_helper.cc

Index: chrome/browser/chromeos/settings/device_settings_test_helper.cc
diff --git a/chrome/browser/chromeos/settings/device_settings_test_helper.cc b/chrome/browser/chromeos/settings/device_settings_test_helper.cc
index e089725e6d3c075bc1a8ffbd9e6e58047186e21d..8aa4311b516b21154937dd95ae42ad6b68248627 100644
--- a/chrome/browser/chromeos/settings/device_settings_test_helper.cc
+++ b/chrome/browser/chromeos/settings/device_settings_test_helper.cc
@@ -203,9 +203,7 @@ ScopedDeviceSettingsTestHelper::~ScopedDeviceSettingsTestHelper() {
 }
 
 DeviceSettingsTestBase::DeviceSettingsTestBase()
-    : ui_thread_(content::BrowserThread::UI, &loop_),
-      file_thread_(content::BrowserThread::FILE, &loop_),
-      user_manager_(new FakeUserManager()),
+    : user_manager_(new FakeUserManager()),
       user_manager_enabler_(user_manager_),
       owner_key_util_(new MockOwnerKeyUtil()),
       fake_dbus_thread_manager_(new FakeDBusThreadManager()) {
@@ -221,7 +219,7 @@ void DeviceSettingsTestBase::SetUp() {
   chromeos::DBusThreadManager::InitializeForTesting(fake_dbus_thread_manager_);
 
   NetworkHandler::Initialize();
-  loop_.RunUntilIdle();
+  base::RunLoop().RunUntilIdle();
 
   device_policy_.payload().mutable_metrics_enabled()->set_metrics_enabled(
       false);