Standardize usage of virtual/override/final specifiers.

media/cast/net/rtcp/receiver_rtcp_event_subscriber_unittest.cc

Index: media/cast/net/rtcp/receiver_rtcp_event_subscriber_unittest.cc
diff --git a/media/cast/net/rtcp/receiver_rtcp_event_subscriber_unittest.cc b/media/cast/net/rtcp/receiver_rtcp_event_subscriber_unittest.cc
index 422340cb9266abf4b2ad074fbbdfb31c72744b5f..35b72a78c26e135f4806857d2491a9da370d5d53 100644
--- a/media/cast/net/rtcp/receiver_rtcp_event_subscriber_unittest.cc
+++ b/media/cast/net/rtcp/receiver_rtcp_event_subscriber_unittest.cc
@@ -33,9 +33,9 @@ class ReceiverRtcpEventSubscriberTest : public ::testing::Test {
             task_runner_,
             task_runner_)) {}
 
-  virtual ~ReceiverRtcpEventSubscriberTest() {}
+  ~ReceiverRtcpEventSubscriberTest() override {}
 
-  virtual void TearDown() override {
+  void TearDown() override {
     if (event_subscriber_) {
       cast_environment_->Logging()->RemoveRawEventSubscriber(
           event_subscriber_.get());