Standardize usage of virtual/override/final in mojo/

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

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "mojo/public/cpp/environment/environment.h"
 #include "mojo/public/cpp/test_support/test_utils.h"
 #include "mojo/public/cpp/utility/run_loop.h"
 #include "mojo/public/interfaces/bindings/tests/sample_import.mojom.h"
 #include "mojo/public/interfaces/bindings/tests/sample_interfaces.mojom.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace mojo {
 namespace test {
 namespace {
 
 class ProviderImpl : public InterfaceImpl<sample::Provider> {
  public:
-  virtual void EchoString(const String& a,
-                          const Callback<void(String)>& callback) override {
+  void EchoString(const String& a,
+                  const Callback<void(String)>& callback) override {
     Callback<void(String)> callback_copy;
     // Make sure operator= is used.
     callback_copy = callback;
     callback_copy.Run(a);
   }
 
-  virtual void EchoStrings(
-      const String& a,
-      const String& b,
-      const Callback<void(String, String)>& callback) override {
+  void EchoStrings(const String& a,
+                   const String& b,
+                   const Callback<void(String, String)>& callback) override {
     callback.Run(a, b);
   }
 
-  virtual void EchoMessagePipeHandle(
+  void EchoMessagePipeHandle(
       ScopedMessagePipeHandle a,
       const Callback<void(ScopedMessagePipeHandle)>& callback) override {
     callback.Run(a.Pass());
   }
 
-  virtual void EchoEnum(sample::Enum a,
-                        const Callback<void(sample::Enum)>& callback) override {
+  void EchoEnum(sample::Enum a,
+                const Callback<void(sample::Enum)>& callback) override {
     callback.Run(a);
   }
 };
 
 class StringRecorder {
  public:
   explicit StringRecorder(std::string* buf) : buf_(buf) {}
   void Run(const String& a) const { *buf_ = a; }
   void Run(const String& a, const String& b) const {
     *buf_ = a.get() + b.get();
@@ skipping 83 matching lines @@
   provider->EchoEnum(sample::ENUM_VALUE, EnumRecorder(&value));
 
   PumpMessages();
 
   EXPECT_EQ(sample::ENUM_VALUE, value);
 }
 
 }  // namespace
 }  // namespace test
 }  // namespace mojo