Standardize usage of virtual/override/final in mojo/

mojo/spy/spy_server_impl.h

Index: mojo/spy/spy_server_impl.h
diff --git a/mojo/spy/spy_server_impl.h b/mojo/spy/spy_server_impl.h
index 20d355e2e25a187fefc247078110fd2ccb44d305..9c1f1ce92bac5ffb2d9526fc6ed7e6cb80af9604 100644
--- a/mojo/spy/spy_server_impl.h
+++ b/mojo/spy/spy_server_impl.h
@@ -21,20 +21,19 @@ class SpyServerImpl :
   SpyServerImpl();
 
   // spy_api::SpyServer implementation.
-  virtual void StartSession(
-      spy_api::VersionPtr version,
-      const mojo::Callback<void(spy_api::Result,
-                                mojo::String)>& callback) override;
+  void StartSession(spy_api::VersionPtr version,
+                    const mojo::Callback<void(spy_api::Result, mojo::String)>&
+                        callback) override;
 
-  virtual void StopSession(
+  void StopSession(
       const mojo::Callback<void(spy_api::Result)>& callback) override;
 
-  virtual void TrackConnection(
+  void TrackConnection(
       uint32_t id,
       spy_api::ConnectionOptions options,
       const mojo::Callback<void(spy_api::Result)>& callback) override;
 
-  virtual void OnConnectionError() override;
+  void OnConnectionError() override;
 
   // SpyServerImpl own methods.
   void OnIntercept(const GURL& url);
@@ -43,7 +42,7 @@ class SpyServerImpl :
 
  private:
   friend class base::RefCounted<SpyServerImpl>;
-  virtual ~SpyServerImpl();
+  ~SpyServerImpl() override;
 
   // Item models the entities that we track by IDs.
   struct Item;