Standardize usage of virtual/override/final in chrome/browser/extensions/

chrome/browser/extensions/api/webrtc_audio_private/webrtc_audio_private_browsertest.cc

 // Copyright 2013 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 "base/json/json_writer.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/synchronization/waitable_event.h"
 #include "base/threading/platform_thread.h"
@@ skipping 59 matching lines @@
       *audio_playing = true;
   }
 };
 
 class WebrtcAudioPrivateTest : public AudioWaitingExtensionTest {
  public:
   WebrtcAudioPrivateTest()
       : enumeration_event_(false, false) {
   }
 
-  virtual void SetUpOnMainThread() override {
+  void SetUpOnMainThread() override {
     AudioWaitingExtensionTest::SetUpOnMainThread();
     // Needs to happen after chrome's schemes are added.
     source_url_ = GURL("chrome-extension://fakeid012345678/fakepage.html");
   }
 
  protected:
   std::string InvokeGetActiveSink(int tab_id) {
     base::ListValue parameters;
     parameters.AppendInteger(tab_id);
     std::string parameter_string;
@@ skipping 319 matching lines @@
   title_watcher.AlsoWaitForTitle(base::ASCIIToUTF16("failure"));
   base::string16 result = title_watcher.WaitAndGetTitle();
   EXPECT_EQ(base::ASCIIToUTF16("success"), result);
 
   g_browser_process->webrtc_log_uploader()->OverrideUploadWithBufferForTesting(
       NULL);
 }
 #endif  // defined(GOOGLE_CHROME_BUILD) || defined(ENABLE_HANGOUT_SERVICES_EXTENSION)
 
 }  // namespace extensions