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

Source/core/dom/custom/CustomElementMicrotaskResolutionStep.h

 /*
  * Copyright (C) 2013 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:
  *
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 30 matching lines @@
 namespace blink {
 
 class CustomElementRegistrationContext;
 class Element;
 
 class CustomElementMicrotaskResolutionStep : public CustomElementMicrotaskStep {
     WTF_MAKE_NONCOPYABLE(CustomElementMicrotaskResolutionStep);
 public:
     static PassOwnPtrWillBeRawPtr<CustomElementMicrotaskResolutionStep> create(PassRefPtrWillBeRawPtr<CustomElementRegistrationContext>, PassRefPtrWillBeRawPtr<Element>, const CustomElementDescriptor&);
 
-    virtual ~CustomElementMicrotaskResolutionStep();
+    ~CustomElementMicrotaskResolutionStep() override;
 
     DECLARE_VIRTUAL_TRACE();
 
 private:
     CustomElementMicrotaskResolutionStep(PassRefPtrWillBeRawPtr<CustomElementRegistrationContext>, PassRefPtrWillBeRawPtr<Element>, const CustomElementDescriptor&);
 
-    virtual Result process() override;
+    Result process() override;
 
 #if !defined(NDEBUG)
-    virtual void show(unsigned indent) override;
+    void show(unsigned indent) override;
 #endif
 
     RefPtrWillBeMember<CustomElementRegistrationContext> m_context;
     RefPtrWillBeMember<Element> m_element;
     CustomElementDescriptor m_descriptor;
 };
 
 } // namespace blink
 
 #endif // CustomElementMicrotaskResolutionStep_h