Revert of Support base::test::ScopedTaskEnvironment and content::TestBrowserThreadBundle in the same scope.

content/public/test/test_browser_thread_bundle_unittest.cc

-// Copyright 2017 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 "content/public/test/test_browser_thread_bundle.h"
-
-#include "base/message_loop/message_loop.h"
-#include "base/test/scoped_task_environment.h"
-#include "testing/gtest/include/gtest/gtest.h"
-
-namespace content {
-
-TEST(TestBrowserThreadBundle, ScopedTaskEnvironmentAndTestBrowserThreadBundle) {
-  base::test::ScopedTaskEnvironment scoped_task_environment(
-      base::test::ScopedTaskEnvironment::MainThreadType::UI);
-  TestBrowserThreadBundle test_browser_thread_bundle;
-}
-
-TEST(TestBrowserThreadBundleTest, MessageLoopTypeMismatch) {
-  base::MessageLoopForUI message_loop;
-  EXPECT_DEATH(
-      {
-        TestBrowserThreadBundle test_browser_thread_bundle(
-            TestBrowserThreadBundle::IO_MAINLOOP);
-      },
-      "Check failed");
-}
-
-TEST(TestBrowserThreadBundleTest, MultipleTestBrowserThreadBundle) {
-  TestBrowserThreadBundle test_browser_thread_bundle;
-  EXPECT_DEATH({ TestBrowserThreadBundle other_test_browser_thread_bundle; },
-               "Check failed");
-}
-
-}  // namespace content