Merge 141226

Source/WebCore/platform/ScrollView.cpp

 /*
  * Copyright (C) 2006, 2007, 2008 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
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 584 matching lines @@
 
         if (m_scrollbarsSuppressed)
             m_verticalScrollbar->setSuppressInvalidation(true);
         m_verticalScrollbar->setEnabled(contentsHeight() > clientHeight);
         m_verticalScrollbar->setSteps(Scrollbar::pixelsPerLineStep(), pageStep);
         m_verticalScrollbar->setProportion(clientHeight, contentsHeight());
         if (m_scrollbarsSuppressed)
             m_verticalScrollbar->setSuppressInvalidation(false);
     }
 
-    if (hasHorizontalScrollbar != (m_horizontalScrollbar != 0) || hasVerticalScrollbar != (m_verticalScrollbar != 0)) {
+    if (hasHorizontalScrollbar != newHasHorizontalScrollbar || hasVerticalScrollbar != newHasVerticalScrollbar) {
         // FIXME: Is frameRectsChanged really necessary here? Have any frame rects changed?
         frameRectsChanged();
         positionScrollbarLayers();
         updateScrollCorner();
         if (!m_horizontalScrollbar && !m_verticalScrollbar)
             invalidateScrollCornerRect(oldScrollCornerRect);
     }
 
     IntPoint adjustedScrollPosition = IntPoint(desiredOffset);
 
@@ skipping 806 matching lines @@
 }
 
 bool ScrollView::platformIsOffscreen() const
 {
     return false;
 }
 
 #endif
 
 }