Standardize usage of virtual/override/final in sync/

sync/engine/net/server_connection_manager.h

Index: sync/engine/net/server_connection_manager.h
diff --git a/sync/engine/net/server_connection_manager.h b/sync/engine/net/server_connection_manager.h
index f7a7575c3052564903c1791ab66cef22e67336a7..44edc4843511f2eb323e8b4cd2682190f71146d1 100644
--- a/sync/engine/net/server_connection_manager.h
+++ b/sync/engine/net/server_connection_manager.h
@@ -183,7 +183,7 @@ class SYNC_EXPORT_PRIVATE ServerConnectionManager : public CancelationObserver {
                           bool use_ssl,
                           CancelationSignal* cancelation_signal);
 
-  virtual ~ServerConnectionManager();
+  ~ServerConnectionManager() override;
 
   // POSTS buffer_in and reads a response into buffer_out. Uses our currently
   // set auth token in our headers.
@@ -217,7 +217,7 @@ class SYNC_EXPORT_PRIVATE ServerConnectionManager : public CancelationObserver {
   // We expect this to get called on a different thread than the valid
   // ThreadChecker thread, as we want to kill any pending http traffic without
   // having to wait for the request to complete.
-  virtual void OnSignalReceived() override final;
+  void OnSignalReceived() final;
 
   void set_client_id(const std::string& client_id) {
     DCHECK(thread_checker_.CalledOnValidThread());