Merge 94107

Source/WebCore/rendering/RenderBox.cpp

Index: Source/WebCore/rendering/RenderBox.cpp
===================================================================
--- Source/WebCore/rendering/RenderBox.cpp	(revision 94130)
+++ Source/WebCore/rendering/RenderBox.cpp	(working copy)
@@ -200,6 +200,11 @@
     if (style() && (style()->logicalHeight().isPercent() || style()->logicalMinHeight().isPercent() || style()->logicalMaxHeight().isPercent()))
         RenderBlock::removePercentHeightDescendant(this);
 
+    // If this renderer is owning renderer for the frameview's custom scrollbars,
+    // we need to clear it from the scrollbar. See webkit bug 64737.
+    if (style() && style()->hasPseudoStyle(SCROLLBAR) && frame() && frame()->view())
+        frame()->view()->clearOwningRendererForCustomScrollbars(this);
+
     // If the following assertion fails, logicalHeight()/logicalMinHeight()/
     // logicalMaxHeight() values are changed from a percent value to a non-percent
     // value during laying out. It causes a use-after-free bug.