HTMLSelectElement size type changed to unsigned

Source/core/layout/LayoutListBox.h

 /*
  * This file is part of the select element layoutObject in WebCore.
  *
  * Copyright (C) 2006, 2007, 2009 Apple 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:
  *
  * 1.  Redistributions of source code must retain the above copyright
@@ skipping 24 matching lines @@
 
 namespace blink {
 
 class HTMLSelectElement;
 
 class LayoutListBox final : public LayoutBlockFlow {
 public:
     explicit LayoutListBox(Element*);
     virtual ~LayoutListBox();
 
-    int size() const;
+    unsigned size() const;
 
     // Unlike scrollRectToVisible this will not scroll parent boxes.
     void scrollToRect(const LayoutRect&);
 
     virtual const char* name() const override { return "LayoutListBox"; }
 
 private:
     HTMLSelectElement* selectElement() const;
 
     virtual bool isOfType(LayoutObjectType type) const override { return type == LayoutObjectListBox || LayoutBlockFlow::isOfType(type); }
 
     virtual void computeLogicalHeight(LayoutUnit logicalHeight, LayoutUnit logicalTop, LogicalExtentComputedValues&) const override;
     virtual void computeIntrinsicLogicalWidths(LayoutUnit& minLogicalWidth, LayoutUnit& maxLogicalWidth) const override;
 
     virtual void stopAutoscroll() override;
 
     LayoutUnit defaultItemHeight() const;
     LayoutUnit itemHeight() const;
 };
 
 DEFINE_LAYOUT_OBJECT_TYPE_CASTS(LayoutListBox, isListBox());
 
 } // namepace blink
 
 #endif // LayoutListBox_h