Standardize usage of virtual/override/final specifiers.

chrome/browser/prerender/prerender_tracker_unittest.cc

 // Copyright (c) 2012 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.
 
 #include <set>
 #include <utility>
 
 #include "base/files/file_path.h"
 #include "base/logging.h"
 #include "base/message_loop/message_loop.h"
@@ skipping 157 matching lines @@
   static const int kDefaultRouteId = 100;
 
   PrerenderTrackerTest() :
       ui_thread_(BrowserThread::UI, &message_loop_),
       io_thread_(BrowserThread::IO, &message_loop_),
       prerender_manager_(prerender_tracker()),
       test_contents_(&prerender_manager_, kDefaultChildId, kDefaultRouteId) {
     chrome_browser_net::SetUrlRequestMocksEnabled(true);
   }
 
-  virtual ~PrerenderTrackerTest() {
+  ~PrerenderTrackerTest() override {
     chrome_browser_net::SetUrlRequestMocksEnabled(false);
 
     // Cleanup work so the file IO tasks from URLRequestMockHTTPJob
     // are gone.
     content::BrowserThread::GetBlockingPool()->FlushForTesting();
     RunEvents();
   }
 
   PrerenderTracker* prerender_tracker() {
     return g_browser_process->prerender_tracker();
@@ skipping 143 matching lines @@
   // We should have cancelled the prerender.
   EXPECT_EQ(FINAL_STATUS_BAD_DEFERRED_REDIRECT,
             test_contents()->final_status());
 
   // Cleanup work so the prerender is gone.
   test_contents()->Cancel();
   RunEvents();
 }
 
 }  // namespace prerender