Standardize usage of virtual/override/final specifiers.

chrome/browser/media/webrtc_log_util_unittest.cc

Index: chrome/browser/media/webrtc_log_util_unittest.cc
diff --git a/chrome/browser/media/webrtc_log_util_unittest.cc b/chrome/browser/media/webrtc_log_util_unittest.cc
index c6a745759d501e2d1ce66c3d2f547d83977385aa..8519be5914752247ce3926bb4050f44ba18b2598 100644
--- a/chrome/browser/media/webrtc_log_util_unittest.cc
+++ b/chrome/browser/media/webrtc_log_util_unittest.cc
@@ -19,7 +19,7 @@ class WebRtcLogUtilTest : public testing::Test {
   WebRtcLogUtilTest()
       : file_thread_(content::BrowserThread::FILE, &message_loop_) {}
 
-  virtual void SetUp() {
+  void SetUp() override {
     // Create three files. One with modified date as of now, one with date one
     // day younger than the keep limit, one with date one day older than the
     // limit. The two former are expected to be kept and the last to be deleted