Fix virtual/override/final usage in the rest of Source/core/.

Source/core/workers/AbstractWorker.h

Index: Source/core/workers/AbstractWorker.h
diff --git a/Source/core/workers/AbstractWorker.h b/Source/core/workers/AbstractWorker.h
index 6231b9f1853c4da6880b2ad1c5f236a603e33e46..91be9b5eda0abe12e65ae7e701a263e3aad9ad6d 100644
--- a/Source/core/workers/AbstractWorker.h
+++ b/Source/core/workers/AbstractWorker.h
@@ -52,12 +52,12 @@ class CORE_EXPORT AbstractWorker : public EventTargetWithInlineData, public RefC
     WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(AbstractWorker);
 public:
     // EventTarget APIs
-    virtual ExecutionContext* executionContext() const override final { return ActiveDOMObject::executionContext(); }
+    ExecutionContext* executionContext() const final { return ActiveDOMObject::executionContext(); }
 
     DEFINE_STATIC_ATTRIBUTE_EVENT_LISTENER(error);
 
     AbstractWorker(ExecutionContext*);
-    virtual ~AbstractWorker();
+    ~AbstractWorker() override;
 
     DECLARE_VIRTUAL_TRACE();