Update DOM classes to use OVERRIDE / FINAL when needed

Source/core/dom/NamedFlowCollection.h

Index: Source/core/dom/NamedFlowCollection.h
diff --git a/Source/core/dom/NamedFlowCollection.h b/Source/core/dom/NamedFlowCollection.h
index 13f5c6943aaee9b5e3c5900bb52624f00b57cdb2..881cd5dcecaa1788163aba25dda089b1c68ac05f 100644
--- a/Source/core/dom/NamedFlowCollection.h
+++ b/Source/core/dom/NamedFlowCollection.h
@@ -43,7 +43,7 @@ namespace WebCore {
 class Document;
 class DOMNamedFlowCollection;
 
-class NamedFlowCollection : public RefCounted<NamedFlowCollection>, public DocumentLifecycleObserver {
+class NamedFlowCollection FINAL : public RefCounted<NamedFlowCollection>, public DocumentLifecycleObserver {
 public:
     static PassRefPtr<NamedFlowCollection> create(Document* doc) { return adoptRef(new NamedFlowCollection(doc)); }