Standardize usage of virtual/override/final specifiers.

ui/events/x/device_data_manager_x11.h

Index: ui/events/x/device_data_manager_x11.h
diff --git a/ui/events/x/device_data_manager_x11.h b/ui/events/x/device_data_manager_x11.h
index 33a1d0cf60b3506247990d9dbddee4e924006ef2..02da999a1cdffcc3e89bf43bade9d82183e6ca3c 100644
--- a/ui/events/x/device_data_manager_x11.h
+++ b/ui/events/x/device_data_manager_x11.h
@@ -241,12 +241,12 @@ class EVENTS_BASE_EXPORT DeviceDataManagerX11 : public DeviceDataManager {
 
  protected:
   // DeviceHotplugEventObserver:
-  virtual void OnKeyboardDevicesUpdated(
+  void OnKeyboardDevicesUpdated(
       const std::vector<KeyboardDevice>& devices) override;
 
  private:
   DeviceDataManagerX11();
-  virtual ~DeviceDataManagerX11();
+  ~DeviceDataManagerX11() override;
 
   // Initialize the XInput related system information.
   bool InitializeXInputInternal();