Fix virtual/override/final usage in Source/modules/.

Source/modules/gamepad/GamepadDispatcher.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 GamepadDispatcher_h
 #define GamepadDispatcher_h
 
 #include "core/frame/PlatformEventDispatcher.h"
 #include "platform/heap/Handle.h"
 #include "public/platform/WebGamepad.h"
 #include "public/platform/WebGamepadListener.h"
 
 namespace blink {
 
 class WebGamepads;
 
 class GamepadDispatcher final : public GarbageCollectedFinalized<GamepadDispatcher>, public PlatformEventDispatcher, public WebGamepadListener {
     USING_GARBAGE_COLLECTED_MIXIN(GamepadDispatcher);
 public:
     static GamepadDispatcher& instance();
-    virtual ~GamepadDispatcher();
+    ~GamepadDispatcher() override;
 
     void sampleGamepads(WebGamepads&);
 
     struct ConnectionChange {
         WebGamepad pad;
         unsigned index;
     };
 
     const ConnectionChange& latestConnectionChange() const { return m_latestChange; }
 
     DECLARE_VIRTUAL_TRACE();
 
 private:
     GamepadDispatcher();
 
     // WebGamepadListener
-    virtual void didConnectGamepad(unsigned index, const WebGamepad&) override;
-    virtual void didDisconnectGamepad(unsigned index, const WebGamepad&) override;
+    void didConnectGamepad(unsigned index, const WebGamepad&) override;
+    void didDisconnectGamepad(unsigned index, const WebGamepad&) override;
 
     // PlatformEventDispatcher
-    virtual void startListening() override;
-    virtual void stopListening() override;
+    void startListening() override;
+    void stopListening() override;
 
     void dispatchDidConnectOrDisconnectGamepad(unsigned index, const WebGamepad&, bool connected);
 
     ConnectionChange m_latestChange;
 };
 
 } // namespace blink
 
 #endif