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

Source/core/plugins/testing/DictionaryPluginPlaceholder.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef DictionaryPluginPlaceholder_h
 #define DictionaryPluginPlaceholder_h
 
 #include "core/html/shadow/PluginPlaceholderElement.h"
 #include "core/plugins/PluginPlaceholder.h"
 #include "core/testing/PluginPlaceholderOptions.h"
@@ skipping 12 matching lines @@
         if (options.hasMessage())
             placeholder->setMessage(options.message());
 
         if (options.hasCloseable())
             placeholder->setIsCloseable(options.closeable());
 
         return adoptPtrWillBeNoop(new DictionaryPluginPlaceholder(placeholder.release()));
     }
 
 #if !ENABLE(OILPAN)
-    virtual ~DictionaryPluginPlaceholder() override { }
+    ~DictionaryPluginPlaceholder() override { }
 #endif
     DEFINE_INLINE_VIRTUAL_TRACE() { visitor->trace(m_pluginPlaceholderElement); }
 
-    virtual void loadIntoContainer(ContainerNode& container) override
+    void loadIntoContainer(ContainerNode& container) override
     {
         container.removeChildren();
         container.appendChild(m_pluginPlaceholderElement, ASSERT_NO_EXCEPTION);
     }
 
 private:
     DictionaryPluginPlaceholder(PassRefPtrWillBeRawPtr<PluginPlaceholderElement> element) : m_pluginPlaceholderElement(element) { }
 
     RefPtrWillBeMember<PluginPlaceholderElement> m_pluginPlaceholderElement;
 };
 
 } // namespace blink
 
 #endif // DictionaryPluginPlaceholder_h