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

chrome/browser/media/chrome_webrtc_video_quality_browsertest.cc

Index: chrome/browser/media/chrome_webrtc_video_quality_browsertest.cc
diff --git a/chrome/browser/media/chrome_webrtc_video_quality_browsertest.cc b/chrome/browser/media/chrome_webrtc_video_quality_browsertest.cc
index 3961d3510814857c6fbcf210415da4c958716649..bc0728cc04f1a3c4c961c2a222f8200ec2605041 100644
--- a/chrome/browser/media/chrome_webrtc_video_quality_browsertest.cc
+++ b/chrome/browser/media/chrome_webrtc_video_quality_browsertest.cc
@@ -102,13 +102,13 @@ class WebRtcVideoQualityBrowserTest : public WebRtcTestBase,
     test_config_ = GetParam();
   }
 
-  virtual void SetUpInProcessBrowserTestFixture() override {
+  void SetUpInProcessBrowserTestFixture() override {
     DetectErrorsInJavaScript();  // Look for errors in our rather complex js.
 
     ASSERT_TRUE(temp_working_dir_.CreateUniqueTempDir());
   }
 
-  virtual void SetUpCommandLine(CommandLine* command_line) override {
+  void SetUpCommandLine(CommandLine* command_line) override {
     // Set up the command line option with the expected file name. We will check
     // its existence in HasAllRequiredResources().
     webrtc_reference_video_y4m_ = test::GetReferenceFilesDir()