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

Source/core/workers/DedicatedWorkerGlobalScope.cpp

 /*
  * Copyright (C) 2009 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 78 matching lines @@
     static PassOwnPtr<UseCounterTask> createCount(UseCounter::Feature feature) { return adoptPtr(new UseCounterTask(feature, false)); }
     static PassOwnPtr<UseCounterTask> createDeprecation(UseCounter::Feature feature) { return adoptPtr(new UseCounterTask(feature, true)); }
 
 private:
     UseCounterTask(UseCounter::Feature feature, bool isDeprecation)
         : m_feature(feature)
         , m_isDeprecation(isDeprecation)
     {
     }
 
-    virtual void performTask(ExecutionContext* context) override
+    void performTask(ExecutionContext* context) override
     {
         ASSERT(context->isDocument());
         if (m_isDeprecation)
             UseCounter::countDeprecation(context, m_feature);
         else
             UseCounter::count(context, m_feature);
     }
 
     UseCounter::Feature m_feature;
     bool m_isDeprecation;
 };
 
 void DedicatedWorkerGlobalScope::countFeature(UseCounter::Feature feature) const
 {
     thread()->workerObjectProxy().postTaskToMainExecutionContext(UseCounterTask::createCount(feature));
 }
 
 void DedicatedWorkerGlobalScope::countDeprecation(UseCounter::Feature feature) const
 {
     thread()->workerObjectProxy().postTaskToMainExecutionContext(UseCounterTask::createDeprecation(feature));
 }
 
 DEFINE_TRACE(DedicatedWorkerGlobalScope)
 {
     WorkerGlobalScope::trace(visitor);
 }
 
 } // namespace blink