Fix invalidation during painting of scrollbars

Source/core/layout/LayoutFlexibleBox.cpp

 /*
  * Copyright (C) 2011 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 566 matching lines @@
 }
 
 LayoutPoint LayoutFlexibleBox::flowAwareLocationForChild(LayoutBox& child) const
 {
     return isHorizontalFlow() ? child.location() : child.location().transposedPoint();
 }
 
 void LayoutFlexibleBox::setFlowAwareLocationForChild(LayoutBox& child, const LayoutPoint& location)
 {
     if (isHorizontalFlow())
-        child.setLocation(location);
+        child.setLocationAndUpdateOverflowControlsIfNeeded(location);
     else
-        child.setLocation(location.transposedPoint());
+        child.setLocationAndUpdateOverflowControlsIfNeeded(location.transposedPoint());
 }
 
 LayoutUnit LayoutFlexibleBox::mainAxisBorderAndPaddingExtentForChild(LayoutBox& child) const
 {
     return isHorizontalFlow() ? child.borderAndPaddingWidth() : child.borderAndPaddingHeight();
 }
 
 static inline bool preferredMainAxisExtentDependsOnLayout(const Length& flexBasis, bool hasInfiniteLineLength)
 {
     return flexBasis.isAuto() || (flexBasis.isPercent() && hasInfiniteLineLength);
@@ skipping 800 matching lines @@
             ASSERT(child);
             LayoutUnit lineCrossAxisExtent = lineContexts[lineNumber].crossAxisExtent;
             LayoutUnit originalOffset = lineContexts[lineNumber].crossAxisOffset - crossAxisStartEdge;
             LayoutUnit newOffset = contentExtent - originalOffset - lineCrossAxisExtent;
             adjustAlignmentForChild(*child, newOffset - originalOffset);
         }
     }
 }
 
 }