Make collection caching code more consistent

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 1117 matching lines @@
     void updateFocusAppearanceTimerFired(Timer<Document>*);
     void updateBaseURL();
 
     void executeScriptsWaitingForResourcesTimerFired(Timer<Document>*);
 
     void loadEventDelayTimerFired(Timer<Document>*);
     void pluginLoadingTimerFired(Timer<Document>*);
 
     PageVisibilityState pageVisibilityState() const;
 
-    PassRefPtrWillBeRawPtr<HTMLCollection> ensureCachedCollection(CollectionType);
-
     // Note that dispatching a window load event may cause the LocalDOMWindow to be detached from
     // the LocalFrame, so callers should take a reference to the LocalDOMWindow (which owns us) to
     // prevent the Document from getting blown away from underneath them.
     void dispatchWindowLoadEvent();
 
     void addListenerType(ListenerType listenerType) { m_listenerTypes |= listenerType; }
     void addMutationEventListenerTypeIfEnabled(ListenerType);
 
     void didAssociateFormControlsTimerFired(Timer<Document>*);
 
@@ skipping 280 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