PlzNavigate: Refactor unit test helper functions

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 "base/macros.h"
+#include "base/memory/scoped_ptr.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.
+scoped_ptr<StreamHandle> MakeEmptyStream();
+
+void EnableBrowserSideNavigation();
+
+}  // namespace content
+
+#endif  // CONTENT_TEST_BROWSER_SIDE_NAVIGATION_TEST_UTILS_H_