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

Source/core/plugins/testing/DictionaryPluginPlaceholder.h

Index: Source/core/plugins/testing/DictionaryPluginPlaceholder.h
diff --git a/Source/core/plugins/testing/DictionaryPluginPlaceholder.h b/Source/core/plugins/testing/DictionaryPluginPlaceholder.h
index 10b5da32f92703fa82d0a35e2a8e7b1049bf41bf..60ba5046ecb46d19f8f087ca7ff13a6df3a84050 100644
--- a/Source/core/plugins/testing/DictionaryPluginPlaceholder.h
+++ b/Source/core/plugins/testing/DictionaryPluginPlaceholder.h
@@ -30,11 +30,11 @@ public:
     }
 
 #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);