mBits |= ROW_SPAN;
mBits |= ROW_SPAN_0;
inline void CellData::SetZeroRowSpan(PRBool aIsZeroSpan){  if (SPAN == (SPAN & mBits)) {    if (aIsZeroSpan) {      mBits |= ROW_SPAN;    }    else {      mBits &= ~ROW_SPAN;    }  }}