[bindings] Avoid using custom binding for HTMLOptionsCollection.length attribute

Source/core/html/HTMLSelectElement.cpp

 /*
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2009, 2010, 2011 Apple Inc. All rights reserved.
  *           (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  * Copyright (C) 2010 Google Inc. All rights reserved.
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  *
@@ skipping 468 matching lines @@
     if (!exceptionState.hadException()) {
         add(element, before, exceptionState);
         if (diff >= 0 && option->selected())
             optionSelectionStateChanged(option, true);
     }
 }
 
 void HTMLSelectElement::setLength(unsigned newLen, ExceptionState& exceptionState)
 {
     if (newLen > maxSelectItems)
-        newLen = maxSelectItems;
+        return;
     int diff = length() - newLen;
 
     if (diff < 0) { // Add dummy elements.
         do {
             appendChild(document().createElement(optionTag, false), exceptionState);
             if (exceptionState.hadException())
                 break;
         } while (++diff);
     } else {
         const WillBeHeapVector<RawPtrWillBeMember<HTMLElement>>& items = listItems();
@@ skipping 1280 matching lines @@
     int focusedIndex = activeSelectionEndListIndex();
     if (focusedIndex < 0)
         focusedIndex = firstSelectableListIndex();
     if (focusedIndex < 0)
         return nullptr;
     HTMLElement* focused = listItems()[focusedIndex];
     return isHTMLOptionElement(focused) ? toHTMLOptionElement(focused) : nullptr;
 }
 
 } // namespace