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

Source/web/WebHelperPluginImpl.h

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 35 matching lines @@
 class WebPluginContainerImpl;
 
 // Utility class to host helper plugins for media. Internally, it creates a detached
 // HTMLPluginElement to host the plugin and uses FrameLoaderClient::createPlugin() to instantiate
 // the requested plugin.
 class WebHelperPluginImpl final : public WebHelperPlugin {
     WTF_MAKE_NONCOPYABLE(WebHelperPluginImpl);
     WTF_MAKE_FAST_ALLOCATED(WebHelperPluginImpl);
 public:
     // WebHelperPlugin methods:
-    virtual WebPlugin* getPlugin() override;
-    virtual void destroy() override;
+    WebPlugin* getPlugin() override;
+    void destroy() override;
 
 private:
     friend class WebHelperPlugin;
 
     WebHelperPluginImpl();
-    virtual ~WebHelperPluginImpl();
+    ~WebHelperPluginImpl() override;
 
     bool initialize(const String& pluginType, WebLocalFrameImpl*);
     void reallyDestroy(Timer<WebHelperPluginImpl>*);
 
     Timer<WebHelperPluginImpl> m_destructionTimer;
     RefPtrWillBePersistent<HTMLObjectElement> m_objectElement;
     RefPtrWillBePersistent<WebPluginContainerImpl> m_pluginContainer;
 };
 
 } // namespace blink
 
 #endif // WebHelperPluginImpl_h