Don't updateRenderTree in the middle of a DOM insertion.

Source/core/html/HTMLSelectElement.h

 /*
  * 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) 2000 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2010 Google Inc. 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
@@ skipping 158 matching lines @@
 
     virtual bool isOptionalFormControl() const override { return !isRequiredFormControl(); }
     virtual bool isRequiredFormControl() const override;
 
     bool hasPlaceholderLabelOption() const;
 
     enum SelectOptionFlag {
         DeselectOtherOptions = 1 << 0,
         DispatchInputAndChangeEvent = 1 << 1,
         UserDriven = 1 << 2,
-        DelayScrollToSelection = 1 << 3,
     };
     typedef unsigned SelectOptionFlags;
     void selectOption(int optionIndex, SelectOptionFlags = 0);
     void deselectItemsWithoutValidation(HTMLElement* elementToExclude = 0);
     void parseMultipleAttribute(const AtomicString&);
     int lastSelectedListIndex() const;
     void updateSelectedState(int listIndex, bool multi, bool shift);
     void menuListDefaultEventHandler(Event*);
     void handlePopupOpenKeyboardEvent(Event*);
     bool shouldOpenPopupForKeyDownEvent(KeyboardEvent*);
@@ skipping 34 matching lines @@
     int m_size;
     int m_lastOnChangeIndex;
     int m_activeSelectionAnchorIndex;
     int m_activeSelectionEndIndex;
     bool m_isProcessingUserDrivenChange;
     bool m_multiple;
     bool m_activeSelectionState;
     mutable bool m_shouldRecalcListItems;
     int m_suggestedIndex;
     bool m_isAutofilledByPreview;
-    bool m_scrollToSelectionLater;
 };
 
 } // namespace blink
 
 #endif // HTMLSelectElement_h