Optimize for horizontal writing mode

Source/core/rendering/LayoutState.cpp

 /*
  * Copyright (C) 2007 Apple Inc.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 54 matching lines @@
     if (renderer.isOutOfFlowPositioned() && !fixed) {
         if (RenderObject* container = renderer.container()) {
             if (container->style()->hasInFlowPosition() && container->isRenderInline())
                 m_layoutOffset += toRenderInline(container)->offsetForInFlowPositionedInline(renderer);
         }
     }
     // If we establish a new page height, then cache the offset to the top of the first page.
     // 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;
         m_isPaginated = true;
     } else {
         // If we don't establish a new page height, then propagate the old page height and offset down.
         m_pageLogicalHeight = m_next->m_pageLogicalHeight;
         m_pageLogicalHeightChanged = m_next->m_pageLogicalHeightChanged;
         m_pageOffset = m_next->m_pageOffset;
 
@@ skipping 58 matching lines @@
 }
 
 void LayoutState::addForcedColumnBreak(const RenderBox& child, const LayoutUnit& childLogicalOffset)
 {
     if (!m_columnInfo || m_columnInfo->columnHeight())
         return;
     m_columnInfo->addForcedBreak(pageLogicalOffset(child, childLogicalOffset));
 }
 
 } // namespace blink