Optimize for horizontal writing mode

Source/core/rendering/RenderFlexibleBox.cpp

 /*
  * Copyright (C) 2011 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 745 matching lines @@
             child.setMarginRight(availableAlignmentSpace / 2);
         }
         return true;
     }
     bool shouldAdjustTopOrLeft = true;
     if (isColumnFlow() && !child.style()->isLeftToRightDirection()) {
         // For column flows, only make this adjustment if topOrLeft corresponds to the "before" margin,
         // so that flipForRightToLeftColumn will do the right thing.
         shouldAdjustTopOrLeft = false;
     }
-    if (!isColumnFlow() && child.style()->isFlippedBlocksWritingMode()) {
+    if (!isColumnFlow() && child.style()->slowIsFlippedBlocksWritingMode()) {
         // If we are a flipped writing mode, we need to adjust the opposite side. This is only needed
         // for row flows because this only affects the block-direction axis.
         shouldAdjustTopOrLeft = false;
     }
 
     if (topOrLeft.isAuto()) {
         if (shouldAdjustTopOrLeft)
             adjustAlignmentForChild(child, availableAlignmentSpace);
 
         if (isHorizontal)
@@ skipping 616 matching lines @@
             ASSERT(child);
             LayoutUnit lineCrossAxisExtent = lineContexts[lineNumber].crossAxisExtent;
             LayoutUnit originalOffset = lineContexts[lineNumber].crossAxisOffset - crossAxisStartEdge;
             LayoutUnit newOffset = contentExtent - originalOffset - lineCrossAxisExtent;
             adjustAlignmentForChild(*child, newOffset - originalOffset);
         }
     }
 }
 
 }