Standardize usage of virtual/override/final in mojo/

mojo/public/cpp/bindings/no_interface.h

Index: mojo/public/cpp/bindings/no_interface.h
diff --git a/mojo/public/cpp/bindings/no_interface.h b/mojo/public/cpp/bindings/no_interface.h
index d8143bdfbb586517985d25b1f92d0f05c3d017b2..4c3578926ab7a808062f5a44ea17700e5dbf6bfb 100644
--- a/mojo/public/cpp/bindings/no_interface.h
+++ b/mojo/public/cpp/bindings/no_interface.h
@@ -38,9 +38,9 @@ class NoInterfaceStub : public MessageReceiverWithResponder {
   NoInterfaceStub() {}
   void set_sink(NoInterface* sink) {}
   NoInterface* sink() { return nullptr; }
-  virtual bool Accept(Message* message) override;
-  virtual bool AcceptWithResponder(Message* message,
-                                   MessageReceiver* responder) override;
+  bool Accept(Message* message) override;
+  bool AcceptWithResponder(Message* message,
+                           MessageReceiver* responder) override;
 };
 
 // AnyInterface is for use in cases where any interface would do (e.g., see the