Make scrollWidth and scrollHeight match other DOM measurement APIs

Source/core/dom/Element.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Peter Kelly (pmk@post.com)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2007 David Smith (catfish.man@gmail.com)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012, 2013 Apple Inc. All rights reserved.
  *           (C) 2007 Eric Seidel (eric@webkit.org)
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 701 matching lines @@
 
         if (LocalDOMWindow* window = document().domWindow())
             window->scrollTo(window->scrollX(), newTop);
     }
 }
 
 int Element::scrollWidth()
 {
     document().updateLayoutIgnorePendingStylesheets();
     if (LayoutBox* box = layoutBox())
-        return adjustLayoutUnitForAbsoluteZoom(box->scrollWidth(), *box).toDouble();
+        return adjustLayoutUnitForAbsoluteZoom(box->scrollWidth(), *box).round();
     return 0;
 }
 
 int Element::scrollHeight()
 {
     document().updateLayoutIgnorePendingStylesheets();
     if (LayoutBox* box = layoutBox())
-        return adjustLayoutUnitForAbsoluteZoom(box->scrollHeight(), *box).toDouble();
+        return adjustLayoutUnitForAbsoluteZoom(box->scrollHeight(), *box).round();
     return 0;
 }
 
 void Element::scrollBy(double x, double y)
 {
     ScrollToOptions scrollToOptions;
     scrollToOptions.setLeft(x);
     scrollToOptions.setTop(y);
     scrollBy(scrollToOptions);
 }
@@ skipping 2646 matching lines @@
 {
 #if ENABLE(OILPAN)
     if (hasRareData())
         visitor->trace(elementRareData());
     visitor->trace(m_elementData);
 #endif
     ContainerNode::trace(visitor);
 }
 
 } // namespace blink