Standardize usage of virtual/override/final in content/renderer/

content/renderer/media/peer_connection_tracker.cc

Index: content/renderer/media/peer_connection_tracker.cc
diff --git a/content/renderer/media/peer_connection_tracker.cc b/content/renderer/media/peer_connection_tracker.cc
index d64a62997316942332aec4767233b996fd0c0aa3..38ad62380e43c7d196a578e8c698230b8bc0b2c4 100644
--- a/content/renderer/media/peer_connection_tracker.cc
+++ b/content/renderer/media/peer_connection_tracker.cc
@@ -246,8 +246,7 @@ class InternalStatsObserver : public webrtc::StatsObserver {
   InternalStatsObserver(int lid)
       : lid_(lid){}
 
-  virtual void OnComplete(
-      const std::vector<webrtc::StatsReport>& reports) override {
+  void OnComplete(const std::vector<webrtc::StatsReport>& reports) override {
     base::ListValue list;
 
     for (size_t i = 0; i < reports.size(); ++i) {
@@ -262,7 +261,7 @@ class InternalStatsObserver : public webrtc::StatsObserver {
   }
 
  protected:
-  virtual ~InternalStatsObserver() {}
+  ~InternalStatsObserver() override {}
 
  private:
   int lid_;