Update DOM classes to use OVERRIDE / FINAL when needed

Source/core/dom/NamedFlow.h

Index: Source/core/dom/NamedFlow.h
diff --git a/Source/core/dom/NamedFlow.h b/Source/core/dom/NamedFlow.h
index 75f2bd5765ac6fa530ed3699271b2fea1803cff8..05d76f26c7eafecf94d9a4c02b493c91db1be747 100644
--- a/Source/core/dom/NamedFlow.h
+++ b/Source/core/dom/NamedFlow.h
@@ -45,12 +45,12 @@ class NodeList;
 class RenderNamedFlowThread;
 class ExecutionContext;
 
-class NamedFlow : public RefCounted<NamedFlow>, public ScriptWrappable, public EventTargetWithInlineData {
+class NamedFlow FINAL : public RefCounted<NamedFlow>, public ScriptWrappable, public EventTargetWithInlineData {
     REFCOUNTED_EVENT_TARGET(NamedFlow);
 public:
     static PassRefPtr<NamedFlow> create(PassRefPtr<NamedFlowCollection> manager, const AtomicString& flowThreadName);
 
-    ~NamedFlow();
+    virtual ~NamedFlow();
 
     const AtomicString& name() const;
     bool overset() const;