Early out if the scroll position passed in by js is NaN

Source/core/html/HTMLBodyElement.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Simon Hausmann (hausmann@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2006, 2007, 2008, 2009, 2010 Apple 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
  * License as published by the Free Software Foundation; either
@@ skipping 229 matching lines @@
     if (FrameView* view = document.view())
         return adjustScrollForAbsoluteZoom(view->scrollX(), document.frame()->pageZoomFactor());
     return 0;
 }
 
 void HTMLBodyElement::setScrollLeft(double scrollLeft)
 {
     Document& document = this->document();
     document.updateLayoutIgnorePendingStylesheets();
 
+    if (std::isnan(scrollLeft))
+        return;
+
     if (RuntimeEnabledFeatures::scrollTopLeftInteropEnabled()) {
         RenderBox* render = renderBox();
         if (!render)
             return;
         if (render->hasOverflowClip()) {
             // FIXME: Investigate how are other browsers casting to int (rounding, ceiling, ...).
             render->setScrollLeft(static_cast<int>(scrollLeft * render->style()->effectiveZoom()));
             return;
         }
         if (!document.inQuirksMode())
@@ skipping 27 matching lines @@
     if (FrameView* view = document.view())
         return adjustScrollForAbsoluteZoom(view->scrollY(), document.frame()->pageZoomFactor());
     return 0;
 }
 
 void HTMLBodyElement::setScrollTop(double scrollTop)
 {
     Document& document = this->document();
     document.updateLayoutIgnorePendingStylesheets();
 
+    if (std::isnan(scrollTop))
+        return;
+
     if (RuntimeEnabledFeatures::scrollTopLeftInteropEnabled()) {
         RenderBox* render = renderBox();
         if (!render)
             return;
         if (render->hasOverflowClip()) {
             // FIXME: Investigate how are other browsers casting to int (rounding, ceiling, ...).
             render->setScrollTop(static_cast<int>(scrollTop * render->style()->effectiveZoom()));
             return;
         }
         if (!document.inQuirksMode())
@@ skipping 21 matching lines @@
 int HTMLBodyElement::scrollWidth()
 {
     // Update the document's layout.
     Document& document = this->document();
     document.updateLayoutIgnorePendingStylesheets();
     FrameView* view = document.view();
     return view ? adjustForZoom(view->contentsWidth(), &document) : 0;
 }
 
 } // namespace blink