PlzNavigate: Refactor unit test helper functions

content/test/test_navigation_url_loader_factory.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_TEST_NAVIGATION_URL_LOADER_FACTORY_H_
+#define CONTENT_TEST_TEST_NAVIGATION_URL_LOADER_FACTORY_H_
+
+#include "base/memory/scoped_ptr.h"
+#include "content/browser/loader/navigation_url_loader_factory.h"
+
+namespace content {
+
+class NavigationURLLoader;
+
+// PlzNavigate
+// Manages creation of the NavigationURLLoaders; when registered, all created
+// NavigationURLLoaderss will be TestNavigationURLLoaderss. This automatically
+// registers itself when it goes in scope, and unregisters itself when it goes
+// out of scope. Since you can't have more than one factory registered at a
+// time, you can only have one of these objects at a time.
+class TestNavigationURLLoaderFactory : public NavigationURLLoaderFactory {
+ public:
+  TestNavigationURLLoaderFactory();
+  ~TestNavigationURLLoaderFactory() override;
+
+  // TestNavigationURLLoaderFactory implementation.
+  scoped_ptr<NavigationURLLoader> CreateLoader(
+      BrowserContext* browser_context,
+      int64 frame_tree_node_id,
+      const CommonNavigationParams& common_params,
+      scoped_ptr<NavigationRequestInfo> request_info,
+      ResourceRequestBody* request_body,
+      NavigationURLLoaderDelegate* delegate) override;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(TestNavigationURLLoaderFactory);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_TEST_TEST_NAVIGATION_URL_LOADER_FACTORY_H_