Standardize usage of virtual/override/final in content/

content/shell/renderer/test_runner/gamepad_controller.h

Index: content/shell/renderer/test_runner/gamepad_controller.h
diff --git a/content/shell/renderer/test_runner/gamepad_controller.h b/content/shell/renderer/test_runner/gamepad_controller.h
index cbabf1ca132256bd1bca1476484fe0687eb70bcf..bd3edbb9f9ab1cccdaf1b1ef2f37b507ac07f446 100644
--- a/content/shell/renderer/test_runner/gamepad_controller.h
+++ b/content/shell/renderer/test_runner/gamepad_controller.h
@@ -25,17 +25,16 @@ class GamepadController
       public RendererGamepadProvider {
  public:
   static base::WeakPtr<GamepadController> Create(WebTestDelegate* delegate);
-  virtual ~GamepadController();
+  ~GamepadController() override;
 
   void Reset();
   void Install(blink::WebFrame* frame);
 
   // RendererGamepadProvider implementation.
-  virtual void SampleGamepads(
-      blink::WebGamepads& gamepads) override;
-  virtual bool OnControlMessageReceived(const IPC::Message& msg) override;
-  virtual void SendStartMessage() override;
-  virtual void SendStopMessage() override;
+  void SampleGamepads(blink::WebGamepads& gamepads) override;
+  bool OnControlMessageReceived(const IPC::Message& msg) override;
+  void SendStartMessage() override;
+  void SendStopMessage() override;
 
  private:
   friend class GamepadControllerBindings;