Fix some unit_tests under PlzNavigate

content/test/browser_side_navigation_test_utils.h

-// 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.
-
-#ifndef CONTENT_TEST_BROWSER_SIDE_NAVIGATION_TEST_UTILS_H_
-#define CONTENT_TEST_BROWSER_SIDE_NAVIGATION_TEST_UTILS_H_
-
-#include <memory>
-
-#include "base/macros.h"
-
-namespace content {
-
-class StreamHandle;
-
-// Initializes the browser side navigation test utils. Following this call, all
-// NavigationURLLoader objects created will be TestNavigationURLLoaders instead
-// of NavigationURLloaderImpls. This should be called before any call in the UI
-// thread unit tests that will start a navigation (eg.
-// TestWebContents::NavigateAndCommit).
-void BrowserSideNavigationSetUp();
-
-// Tears down the browser side navigation test utils.
-void BrowserSideNavigationTearDown();
-
-// Returns an empty stream. Used when faking a navigation commit notification
-// from the IO thread with a TestNavigationURLLoader.
-std::unique_ptr<StreamHandle> MakeEmptyStream();
-
-// If a test needs to run with browser side navigation enabled, call this
-// function before doing any setup. In particular, for tests inheriting from
-// RenderViewHostTestHarness, call this function before calling
-// RenderViewHostTestHarness::SetUp.
-void EnableBrowserSideNavigation();
-
-}  // namespace content
-
-#endif  // CONTENT_TEST_BROWSER_SIDE_NAVIGATION_TEST_UTILS_H_