[Prerender] Restore request priorities when swapped in

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 415 matching lines @@
 // thread. Does not modify the behavior or the request job.
 void InterceptRequestAndCount(
     const GURL& url,
     RequestCounter* counter,
     base::Callback<void(net::URLRequest*)> callback_io);
 
 // Makes |url| respond to requests with the contents of |file|.
 void CreateMockInterceptorOnIO(const GURL& url, const base::FilePath& file);
 
 // Makes |url| never respond on the first load, and then with the contents of
-// |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);
+// |file| afterwards. When the first load has been scheduled, runs |callback_io|
+// on the IO thread.
+void CreateHangingFirstRequestInterceptor(
+    const GURL& url,
+    const base::FilePath& file,
+    base::Callback<void(net::URLRequest*)> callback_io);
 
 }  // namespace test_utils
 
 }  // namespace prerender
 
 #endif  // CHROME_BROWSER_PRERENDER_PRERENDER_TEST_UTILS_H_