Optimize for horizontal writing mode

Source/core/rendering/LayoutState.cpp

Index: Source/core/rendering/LayoutState.cpp
diff --git a/Source/core/rendering/LayoutState.cpp b/Source/core/rendering/LayoutState.cpp
index 5a2ba588c863af8ff9a30ec37a578a713a38d08b..c0ccc26e447085c65bc1158002b9d7d61cb03a1e 100644
--- a/Source/core/rendering/LayoutState.cpp
+++ b/Source/core/rendering/LayoutState.cpp
@@ -72,7 +72,7 @@ LayoutState::LayoutState(RenderBox& renderer, const LayoutSize& offset, LayoutUn
     // We can compare this later on to figure out what part of the page we're actually on,
     if (pageLogicalHeight || m_columnInfo || renderer.isRenderFlowThread()) {
         m_pageLogicalHeight = pageLogicalHeight;
-        bool isFlipped = renderer.style()->isFlippedBlocksWritingMode();
+        bool isFlipped = renderer.style()->slowIsFlippedBlocksWritingMode();
         m_pageOffset = LayoutSize(m_layoutOffset.width() + (!isFlipped ? renderer.borderLeft() + renderer.paddingLeft() : renderer.borderRight() + renderer.paddingRight()),
             m_layoutOffset.height() + (!isFlipped ? renderer.borderTop() + renderer.paddingTop() : renderer.borderBottom() + renderer.paddingBottom()));
         m_pageLogicalHeightChanged = pageLogicalHeightChanged;