Fix virtual/override/final usage in Source/core/dom/.

Source/core/dom/DocumentMarker.cpp

 /*
  * Copyright (C) 2011 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 24 matching lines @@
 
 DocumentMarkerDetails::~DocumentMarkerDetails()
 {
 }
 
 class DocumentMarkerDescription final : public DocumentMarkerDetails {
 public:
     static PassRefPtrWillBeRawPtr<DocumentMarkerDescription> create(const String&);
 
     const String& description() const { return m_description; }
-    virtual bool isDescription() const override { return true; }
+    bool isDescription() const override { return true; }
 
 private:
     explicit DocumentMarkerDescription(const String& description)
         : m_description(description)
     {
     }
 
     String m_description;
 };
 
 PassRefPtrWillBeRawPtr<DocumentMarkerDescription> DocumentMarkerDescription::create(const String& description)
 {
     return adoptRefWillBeNoop(new DocumentMarkerDescription(description));
 }
 
 inline DocumentMarkerDescription* toDocumentMarkerDescription(DocumentMarkerDetails* details)
 {
     if (details && details->isDescription())
         return static_cast<DocumentMarkerDescription*>(details);
     return 0;
 }
 
 
 class DocumentMarkerTextMatch final : public DocumentMarkerDetails {
 public:
     static PassRefPtrWillBeRawPtr<DocumentMarkerTextMatch> instanceFor(bool);
 
     bool activeMatch() const { return m_match; }
-    virtual bool isTextMatch() const override { return true; }
+    bool isTextMatch() const override { return true; }
 
 private:
     explicit DocumentMarkerTextMatch(bool match)
         : m_match(match)
     {
     }
 
     bool m_match;
 };
 
@@ skipping 62 matching lines @@
         return details->activeMatch();
     return false;
 }
 
 DEFINE_TRACE(DocumentMarker)
 {
     visitor->trace(m_details);
 }
 
 } // namespace blink