Introduce and use type casting functions for several HTMLCollection types

Source/bindings/v8/custom/V8HTMLCollectionCustom.cpp

 /*
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 27 matching lines @@
 #include "bindings/v8/V8Binding.h"
 #include "core/html/HTMLCollection.h"
 
 namespace WebCore {
 
 v8::Handle<v8::Object> wrap(HTMLCollection* impl, v8::Handle<v8::Object> creationContext, v8::Isolate* isolate)
 {
     ASSERT(impl);
     switch (impl->type()) {
     case FormControls:
-        return wrap(static_cast<HTMLFormControlsCollection*>(impl), creationContext, isolate);
+        return wrap(toHTMLFormControlsCollection(impl), creationContext, isolate);
     case SelectOptions:
-        return wrap(static_cast<HTMLOptionsCollection*>(impl), creationContext, isolate);
+        return wrap(toHTMLOptionsCollection(impl), creationContext, isolate);
     case DocAll:
-        return wrap(static_cast<HTMLAllCollection*>(impl), creationContext, isolate);
+        return wrap(toHTMLAllCollection(impl), creationContext, isolate);
     default:
         break;
     }
 
     return V8HTMLCollection::createWrapper(impl, creationContext, isolate);
 }
 
 } // namespace WebCore