Standardize usage of virtual/override/final in components/

components/gcm_driver/gcm_driver_desktop_unittest.cc

Index: components/gcm_driver/gcm_driver_desktop_unittest.cc
diff --git a/components/gcm_driver/gcm_driver_desktop_unittest.cc b/components/gcm_driver/gcm_driver_desktop_unittest.cc
index 9c8a353aa87c6bee809e1216bdd4ab675905e79b..8d9211bd7a75269d8549922d6b731c677f0cd3e6 100644
--- a/components/gcm_driver/gcm_driver_desktop_unittest.cc
+++ b/components/gcm_driver/gcm_driver_desktop_unittest.cc
@@ -46,11 +46,11 @@ const char kUserID1[] = "user1";
 class FakeGCMConnectionObserver : public GCMConnectionObserver {
  public:
   FakeGCMConnectionObserver();
-  virtual ~FakeGCMConnectionObserver();
+  ~FakeGCMConnectionObserver() override;
 
   // gcm::GCMConnectionObserver implementation:
-  virtual void OnConnected(const net::IPEndPoint& ip_endpoint) override;
-  virtual void OnDisconnected() override;
+  void OnConnected(const net::IPEndPoint& ip_endpoint) override;
+  void OnDisconnected() override;
 
   bool connected() const { return connected_; }