Introduce and use type casting functions for several HTMLCollection types

Source/core/html/HTMLFormControlsCollection.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2010, 2011, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2014 Samsung Electronics. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
@@ skipping 29 matching lines @@
 
 HTMLFormControlsCollection::HTMLFormControlsCollection(ContainerNode& ownerNode)
     : HTMLCollection(ownerNode, FormControls, OverridesItemAfter)
     , m_cachedElement(nullptr)
     , m_cachedElementOffsetInArray(0)
 {
     ASSERT(isHTMLFormElement(ownerNode) || isHTMLFieldSetElement(ownerNode));
     ScriptWrappable::init(this);
 }
 
-PassRefPtrWillBeRawPtr<HTMLFormControlsCollection> HTMLFormControlsCollection::create(ContainerNode& ownerNode, CollectionType)
+PassRefPtrWillBeRawPtr<HTMLFormControlsCollection> HTMLFormControlsCollection::create(ContainerNode& ownerNode, CollectionType type)
 {
+    ASSERT_UNUSED(type, type == FormControls);
     return adoptRefWillBeNoop(new HTMLFormControlsCollection(ownerNode));
 }
 
 HTMLFormControlsCollection::~HTMLFormControlsCollection()
 {
 }
 
 const FormAssociatedElement::List& HTMLFormControlsCollection::formControlElements() const
 {
     ASSERT(isHTMLFormElement(ownerNode()) || isHTMLFieldSetElement(ownerNode()));
@@ skipping 175 matching lines @@
     }
 }
 
 void HTMLFormControlsCollection::trace(Visitor* visitor)
 {
     visitor->trace(m_cachedElement);
     HTMLCollection::trace(visitor);
 }
 
 }