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

Source/core/dom/custom/CustomElementMicrotaskImportStep.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 36 matching lines @@
 // Processes the Custom Elements in an HTML Import. This is a
 // composite step which processes the Custom Elements created by
 // parsing the import, and its sub-imports.
 //
 // This step blocks further Custom Element microtask processing if its
 // import isn't "ready" (finished parsing and running script.)
 class CustomElementMicrotaskImportStep : public CustomElementMicrotaskStep {
     WTF_MAKE_NONCOPYABLE(CustomElementMicrotaskImportStep);
 public:
     static PassOwnPtrWillBeRawPtr<CustomElementMicrotaskImportStep> create(HTMLImportChild*);
-    virtual ~CustomElementMicrotaskImportStep();
+    ~CustomElementMicrotaskImportStep() override;
 
     // API for HTML Imports
     void invalidate();
     void importDidFinishLoading();
 #if !ENABLE(OILPAN)
     WeakPtr<CustomElementMicrotaskImportStep> weakPtr() { return m_weakFactory.createWeakPtr(); }
 #endif
 
     DECLARE_VIRTUAL_TRACE();
 
 private:
     explicit CustomElementMicrotaskImportStep(HTMLImportChild*);
 
     void didUpgradeAllCustomElements();
     bool shouldWaitForImport() const;
 
     // CustomElementMicrotaskStep
-    virtual Result process() override final;
+    Result process() final;
 
 #if !defined(NDEBUG)
-    virtual void show(unsigned indent) override;
+    void show(unsigned indent) override;
 #endif
     WeakPtrWillBeWeakMember<HTMLImportChild> m_import;
 #if !ENABLE(OILPAN)
     WeakPtrFactory<CustomElementMicrotaskImportStep> m_weakFactory;
 #endif
     RefPtrWillBeMember<CustomElementSyncMicrotaskQueue> m_queue;
 };
 
 } // namespace blink
 
 #endif // CustomElementMicrotaskImportStep_h