Enable sticky positioning for table elements.

Source/core/rendering/RenderBox.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2005 Allan Sandfeld Jensen (kde@carewolf.com)
  *           (C) 2005, 2006 Samuel Weinig (sam.weinig@gmail.com)
  * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2013 Adobe Systems Incorporated. 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
@@ skipping 3199 matching lines @@
     // Use viewport as container for top-level fixed-position elements.
     if (style()->position() == FixedPosition && containingBlock->isRenderView()) {
         const RenderView* view = toRenderView(containingBlock);
         if (FrameView* frameView = view->frameView()) {
             LayoutRect viewportRect = frameView->viewportConstrainedVisibleContentRect();
             return containingBlock->isHorizontalWritingMode() ? viewportRect.height() : viewportRect.width();
         }
     }
 
     if (containingBlock->isBox()) {
-        const RenderBlock* cb = toRenderBlock(containingBlock);
+        const RenderBlock* cb = containingBlock->isRenderBlock() ?
+            toRenderBlock(containingBlock) : containingBlock->containingBlock();
         LayoutUnit result = cb->clientLogicalHeight();
         RenderFlowThread* flowThread = flowThreadContainingBlock();
         if (flowThread && containingBlock->isRenderFlowThread() && flowThread->isHorizontalWritingMode() == containingBlock->isHorizontalWritingMode())
             return toRenderFlowThread(containingBlock)->contentLogicalHeightOfFirstRegion();
         return result;
     }
 
     ASSERT(containingBlock->isRenderInline() && containingBlock->isInFlowPositioned());
 
     const RenderInline* flow = toRenderInline(containingBlock);
@@ skipping 1686 matching lines @@
         return 0;
 
     if (!layoutState && !flowThreadContainingBlock())
         return 0;
 
     RenderBlock* containerBlock = containingBlock();
     return containerBlock->offsetFromLogicalTopOfFirstPage() + logicalTop();
 }
 
 } // namespace WebCore