Make it clear a DocumentNameCollection can only contain HTMLElements

Source/core/dom/Document.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
@@ skipping 62 matching lines @@
 class ConsoleMessage;
 class ContentSecurityPolicyResponseHeaders;
 class ContextFeatures;
 class CustomElementMicrotaskRunQueue;
 class CustomElementRegistrationContext;
 class DOMImplementation;
 class DocumentFragment;
 class DocumentLifecycleNotifier;
 class DocumentLoader;
 class DocumentMarkerController;
+class DocumentNameCollection;
 class DocumentParser;
 class DocumentState;
 class DocumentType;
 class Element;
 class ElementDataCache;
 class Event;
 class EventFactoryBase;
 class EventListener;
 template <typename EventType>
 class EventWithHitTestResults;
@@ skipping 263 matching lines @@
     PassRefPtrWillBeRawPtr<HTMLCollection> embeds();
     PassRefPtrWillBeRawPtr<HTMLCollection> applets();
     PassRefPtrWillBeRawPtr<HTMLCollection> links();
     PassRefPtrWillBeRawPtr<HTMLCollection> forms();
     PassRefPtrWillBeRawPtr<HTMLCollection> anchors();
     PassRefPtrWillBeRawPtr<HTMLCollection> scripts();
     PassRefPtrWillBeRawPtr<HTMLAllCollection> allForBinding();
     PassRefPtrWillBeRawPtr<HTMLAllCollection> all();
 
     PassRefPtrWillBeRawPtr<HTMLCollection> windowNamedItems(const AtomicString& name);
-    PassRefPtrWillBeRawPtr<HTMLCollection> documentNamedItems(const AtomicString& name);
+    PassRefPtrWillBeRawPtr<DocumentNameCollection> documentNamedItems(const AtomicString& name);
 
     bool isHTMLDocument() const { return m_documentClasses & HTMLDocumentClass; }
     bool isXHTMLDocument() const { return m_documentClasses & XHTMLDocumentClass; }
     bool isXMLDocument() const { return m_documentClasses & XMLDocumentClass; }
     bool isImageDocument() const { return m_documentClasses & ImageDocumentClass; }
     bool isSVGDocument() const { return m_documentClasses & SVGDocumentClass; }
     bool isPluginDocument() const { return m_documentClasses & PluginDocumentClass; }
     bool isMediaDocument() const { return m_documentClasses & MediaDocumentClass; }
 
     bool hasSVGRootNode() const;
@@ skipping 1025 matching lines @@
 Node* eventTargetNodeForDocument(Document*);
 
 } // namespace blink
 
 #ifndef NDEBUG
 // Outside the WebCore namespace for ease of invocation from gdb.
 void showLiveDocumentInstances();
 #endif
 
 #endif // Document_h