chrome: Cleanup class/struct forward declarations

chrome/browser/prerender/prerender_test_utils.h

 // Copyright (c) 2016 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 CHROME_BROWSER_PRERENDER_PRERENDER_TEST_UTILS_H_
 #define CHROME_BROWSER_PRERENDER_PRERENDER_TEST_UTILS_H_
 
 #include <deque>
 #include <functional>
 #include <memory>
@@ skipping 13 matching lines @@
 #include "components/safe_browsing_db/test_database_manager.h"
 #include "content/public/browser/browser_thread.h"
 #include "net/test/url_request/url_request_mock_http_job.h"
 #include "net/url_request/url_request_interceptor.h"
 #include "url/gurl.h"
 
 namespace base {
 class FilePath;
 }  // namespace base
 
-namespace net {
-class URLRequest;
-class NetworkDelegate;
-}  // namespace net
-
 namespace prerender {
 
 namespace test_utils {
 
 // Dummy counter class to live on the UI thread for counting requests.
 class RequestCounter : public base::SupportsWeakPtr<RequestCounter> {
  public:
   RequestCounter();
 
   ~RequestCounter();
@@ skipping 333 matching lines @@
 // |file| afterwards. When the first load has been scheduled, runs |callback| on
 // the UI thread.
 void CreateHangingFirstRequestInterceptorOnIO(
     const GURL& url, const base::FilePath& file, base::Closure callback);
 
 }  // namespace test_utils
 
 }  // namespace prerender
 
 #endif  // CHROME_BROWSER_PRERENDER_PRERENDER_TEST_UTILS_H_