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

Source/modules/mediasource/SourceBufferList.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:
  *
  *     * 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 29 matching lines @@
 class GenericEventQueue;
 
 class SourceBufferList final : public RefCountedGarbageCollectedEventTargetWithInlineData<SourceBufferList> {
     REFCOUNTED_GARBAGE_COLLECTED_EVENT_TARGET(SourceBufferList);
     DEFINE_WRAPPERTYPEINFO();
 public:
     static SourceBufferList* create(ExecutionContext* context, GenericEventQueue* asyncEventQueue)
     {
         return new SourceBufferList(context, asyncEventQueue);
     }
-    virtual ~SourceBufferList();
+    ~SourceBufferList() override;
 
     unsigned length() const { return m_list.size(); }
     SourceBuffer* item(unsigned index) const { return (index < m_list.size()) ? m_list[index].get() : 0; }
 
     void add(SourceBuffer*);
     void insert(size_t position, SourceBuffer*);
     void remove(SourceBuffer*);
     size_t find(SourceBuffer* buffer) { return m_list.find(buffer); }
     bool contains(SourceBuffer* buffer) { return m_list.find(buffer) != kNotFound; }
     void clear();
 
     // EventTarget interface
-    virtual const AtomicString& interfaceName() const override;
-    virtual ExecutionContext* executionContext() const override;
+    const AtomicString& interfaceName() const override;
+    ExecutionContext* executionContext() const override;
 
     DECLARE_VIRTUAL_TRACE();
 
 private:
     SourceBufferList(ExecutionContext*, GenericEventQueue*);
 
     void scheduleEvent(const AtomicString&);
 
     RawPtrWillBeMember<ExecutionContext> m_executionContext;
     RawPtrWillBeMember<GenericEventQueue> m_asyncEventQueue;
 
     HeapVector<Member<SourceBuffer>> m_list;
 };
 
 } // namespace blink
 
 #endif // SourceBufferList_h