Ensure tests have an active task runner

chrome/browser/ui/sync/sync_promo_ui_unittest.cc

 // Copyright 2013 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/sync/sync_promo_ui.h"
 
 #include "base/basictypes.h"
 #include "base/command_line.h"
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
 #include "chrome/browser/signin/fake_signin_manager.h"
 #include "chrome/browser/signin/signin_manager_factory.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/test/base/testing_profile.h"
+#include "content/public/test/test_browser_thread_bundle.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 class SyncPromoUITest : public testing::Test {
  public:
   SyncPromoUITest() {}
 
   // testing::Test:
   void SetUp() override {
     testing::Test::SetUp();
     TestingProfile::Builder builder;
     builder.AddTestingFactory(SigninManagerFactory::GetInstance(),
                               FakeSigninManagerBase::Build);
     profile_ = builder.Build();
   }
 
  protected:
   void DisableSync() {
     base::CommandLine::ForCurrentProcess()->AppendSwitch(
         switches::kDisableSync);
   }
 
+  content::TestBrowserThreadBundle thread_bundle_;
   scoped_ptr<TestingProfile> profile_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(SyncPromoUITest);
 };
 
 // Verifies that ShouldShowSyncPromo returns false if sync is disabled by
 // policy.
 TEST_F(SyncPromoUITest, ShouldShowSyncPromoSyncDisabled) {
   DisableSync();
   EXPECT_FALSE(SyncPromoUI::ShouldShowSyncPromo(profile_.get()));
 }
 
 // Verifies that ShouldShowSyncPromo returns true if all conditions to
 // show the promo are met.
 TEST_F(SyncPromoUITest, ShouldShowSyncPromoSyncEnabled) {
 #if defined(OS_CHROMEOS)
   // No sync promo on CrOS.
   EXPECT_FALSE(SyncPromoUI::ShouldShowSyncPromo(profile_.get()));
 #else
   EXPECT_TRUE(SyncPromoUI::ShouldShowSyncPromo(profile_.get()));
 #endif
 }