Since RenderTable::paintBoxDecorations doesn't provide correct bleedAvoidance parameter for paintBackground, both RenderTable::paintBoxDecorations and RenderBox::paintBackground (~RenderBoxModelObject::paintFillLayerExtended) draw box-shadow.
Created attachment 189032 [details] Patch
This is really a patch for Simon, I don't know much about bleedAvoidance.
Comment on attachment 189032 [details] Patch Clearing flags on attachment: 189032 Committed r143690: <http://trac.webkit.org/changeset/143690>
All reviewed patches have been landed. Closing bug.