void RenderNamedFlowThread::updateWritingMode() { RenderRegion* firstRegion = m_regionList.first(); if (!firstRegion) return; if (style()->writingMode() == firstRegion->style()->writingMode()) return; // The first region defines the principal writing mode for the entire flow. RefPtr<RenderStyle> newStyle = RenderStyle::clone(style()); newStyle->setWritingMode(firstRegion->style()->writingMode()); setStyle(newStyle.release()); }