Standardize usage of virtual/override/final in mojo/

mojo/services/test_service/test_time_service_impl.h

 // 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.
 
 #ifndef MOJO_SERVICES_TEST_SERVICE_TEST_TIME_SERVICE_IMPL_H_
 #define MOJO_SERVICES_TEST_SERVICE_TEST_TIME_SERVICE_IMPL_H_
 
 #include "base/memory/scoped_ptr.h"
 #include "mojo/public/cpp/system/macros.h"
 #include "mojo/services/test_service/test_service.mojom.h"
 
 namespace mojo {
 
 class ApplicationConnection;
 
 namespace test {
 
 class TestRequestTrackerClientImpl;
 
 class TestTimeServiceImpl : public InterfaceImpl<TestTimeService> {
  public:
   explicit TestTimeServiceImpl(ApplicationConnection* application);
-  virtual ~TestTimeServiceImpl();
+  ~TestTimeServiceImpl() override;
 
   // |TestTimeService| methods:
-  virtual void GetPartyTime(
+  void GetPartyTime(
       const mojo::Callback<void(int64_t time_usec)>& callback) override;
-  virtual void StartTrackingRequests(
-      const mojo::Callback<void()>& callback) override;
+  void StartTrackingRequests(const mojo::Callback<void()>& callback) override;
 
  private:
   ApplicationConnection* application_;
   scoped_ptr<TestRequestTrackerClientImpl> tracking_;
   MOJO_DISALLOW_COPY_AND_ASSIGN(TestTimeServiceImpl);
 };
 
 }  // namespace test
 }  // namespace mojo
 
 #endif  // MOJO_SERVICES_TEST_SERVICE_TEST_TIME_SERVICE_IMPL_H_