Standardize usage of virtual/override/final in mojo/

mojo/public/cpp/bindings/tests/sample_service_unittest.cc

Index: mojo/public/cpp/bindings/tests/sample_service_unittest.cc
diff --git a/mojo/public/cpp/bindings/tests/sample_service_unittest.cc b/mojo/public/cpp/bindings/tests/sample_service_unittest.cc
index a8ea60d41dc2d91bbe53ce90d82d7e69119b2ab4..0bed5409c5f208a278782c900f618d1af124779f 100644
--- a/mojo/public/cpp/bindings/tests/sample_service_unittest.cc
+++ b/mojo/public/cpp/bindings/tests/sample_service_unittest.cc
@@ -256,7 +256,7 @@ void DumpHex(const uint8_t* bytes, uint32_t num_bytes) {
 
 class ServiceImpl : public Service {
  public:
-  virtual void Frobinate(FooPtr foo, BazOptions baz, PortPtr port) override {
+  void Frobinate(FooPtr foo, BazOptions baz, PortPtr port) override {
     // Users code goes here to handle the incoming Frobinate message.
 
     // We mainly check that we're given the expected arguments.
@@ -275,7 +275,7 @@ class ServiceImpl : public Service {
     }
   }
 
-  virtual void GetPort(mojo::InterfaceRequest<Port> port_request) override {}
+  void GetPort(mojo::InterfaceRequest<Port> port_request) override {}
 };
 
 class ServiceProxyImpl : public ServiceProxy {
@@ -286,7 +286,7 @@ class ServiceProxyImpl : public ServiceProxy {
 
 class SimpleMessageReceiver : public mojo::MessageReceiverWithResponder {
  public:
-  virtual bool Accept(mojo::Message* message) override {
+  bool Accept(mojo::Message* message) override {
     // Imagine some IPC happened here.
 
     if (g_dump_message_as_hex) {
@@ -303,8 +303,8 @@ class SimpleMessageReceiver : public mojo::MessageReceiverWithResponder {
     return stub.Accept(message);
   }
 
-  virtual bool AcceptWithResponder(mojo::Message* message,
-                                   mojo::MessageReceiver* responder) override {
+  bool AcceptWithResponder(mojo::Message* message,
+                           mojo::MessageReceiver* responder) override {
     return false;
   }
 };