Pass a struct to ContainerNode::childrenChanged() instead of separate arguments

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 172 matching lines @@
         SkipBackwards = -1,
         SkipForwards = 1
     };
     int nextValidIndex(int listIndex, SkipDirection, int skip) const;
     int nextSelectableListIndex(int startIndex) const;
     int previousSelectableListIndex(int startIndex) const;
     int firstSelectableListIndex() const;
     int lastSelectableListIndex() const;
     int nextSelectableListIndexPageAway(int startIndex, SkipDirection) const;
 
-    virtual void childrenChanged(bool changedByParser = false, Node* beforeChange = 0, Node* afterChange = 0, int childCountDelta = 0) OVERRIDE;
+    virtual void childrenChanged(const ChildrenChange&) OVERRIDE;
     virtual bool areAuthorShadowsAllowed() const OVERRIDE { return false; }
     virtual void finishParsingChildren() OVERRIDE;
 
     // TypeAheadDataSource functions.
     virtual int indexOfSelectedOption() const OVERRIDE;
     virtual int optionCount() const OVERRIDE;
     virtual String optionAtIndex(int index) const OVERRIDE;
 
     // m_listItems contains HTMLOptionElement, HTMLOptGroupElement, and HTMLHRElement objects.
     mutable WillBeHeapVector<RawPtrWillBeMember<HTMLElement> > m_listItems;
     Vector<bool> m_lastOnChangeSelection;
     Vector<bool> m_cachedStateForActiveSelection;
     TypeAhead m_typeAhead;
     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;
 };
 
 } // namespace
 
 #endif