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

Source/core/plugins/testing/DocumentFragmentPluginPlaceholder.h

Index: Source/core/plugins/testing/DocumentFragmentPluginPlaceholder.h
diff --git a/Source/core/plugins/testing/DocumentFragmentPluginPlaceholder.h b/Source/core/plugins/testing/DocumentFragmentPluginPlaceholder.h
index 7d8300a94c05610f2d312b47e1f077acc473b23f..d89ac0dc4ef9fd06abec652ae333e1f1dc9f0121 100644
--- a/Source/core/plugins/testing/DocumentFragmentPluginPlaceholder.h
+++ b/Source/core/plugins/testing/DocumentFragmentPluginPlaceholder.h
@@ -22,11 +22,11 @@ public:
     }
 
 #if !ENABLE(OILPAN)
-    virtual ~DocumentFragmentPluginPlaceholder() override { }
+    ~DocumentFragmentPluginPlaceholder() override { }
 #endif
     DEFINE_INLINE_VIRTUAL_TRACE() { visitor->trace(m_fragment); }
 
-    virtual void loadIntoContainer(ContainerNode& container) override
+    void loadIntoContainer(ContainerNode& container) override
     {
         RefPtrWillBeRawPtr<Node> clonedFragment = container.document().importNode(m_fragment.get(), true /* deep */, ASSERT_NO_EXCEPTION);
         container.appendChild(clonedFragment.release(), ASSERT_NO_EXCEPTION);