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

Source/web/NavigatorContentUtilsClientImpl.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 NavigatorContentUtilsClientImpl_h
 #define NavigatorContentUtilsClientImpl_h
 
 #include "modules/navigatorcontentutils/NavigatorContentUtilsClient.h"
 #include "platform/weborigin/KURL.h"
 
 namespace blink {
 
 class WebViewImpl;
 
 class NavigatorContentUtilsClientImpl final : public NavigatorContentUtilsClient {
 public:
     static PassOwnPtr<NavigatorContentUtilsClientImpl> create(WebViewImpl*);
-    virtual ~NavigatorContentUtilsClientImpl() { }
+    ~NavigatorContentUtilsClientImpl() override { }
 
-    virtual void registerProtocolHandler(const String& scheme, const KURL&, const String& title) override;
-    virtual CustomHandlersState isProtocolHandlerRegistered(const String& scheme, const KURL&) override;
-    virtual void unregisterProtocolHandler(const String& scheme, const KURL&) override;
+    void registerProtocolHandler(const String& scheme, const KURL&, const String& title) override;
+    CustomHandlersState isProtocolHandlerRegistered(const String& scheme, const KURL&) override;
+    void unregisterProtocolHandler(const String& scheme, const KURL&) override;
 
 private:
     explicit NavigatorContentUtilsClientImpl(WebViewImpl*);
 
     WebViewImpl* m_webView;
 };
 
 } // namespace blink
 
 #endif // NavigatorContentUtilsClientImpl_h