*** DO NOT LAND *** Attempt to understand Regions complexity

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 64 matching lines @@
         else {
             m_clipRect = clipRect;
             m_clipped = true;
         }
 
         m_paintOffset -= renderer->scrolledContentOffset();
     }
 
     // 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()) {
+    if (pageLogicalHeight || m_columnInfo) {
         m_pageLogicalHeight = pageLogicalHeight;
         bool isFlipped = renderer->style()->isFlippedBlocksWritingMode();
         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;
     } 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 16 matching lines @@
         if (!m_shapeInsideInfo && m_next->m_shapeInsideInfo && renderBlock->allowsShapeInsideInfoSharing(m_next->m_shapeInsideInfo->owner()))
             m_shapeInsideInfo = m_next->m_shapeInsideInfo;
     }
 
     m_layoutDelta = m_next->m_layoutDelta;
 #if !ASSERT_DISABLED
     m_layoutDeltaXSaturated = m_next->m_layoutDeltaXSaturated;
     m_layoutDeltaYSaturated = m_next->m_layoutDeltaYSaturated;
 #endif
 
-    m_isPaginated = m_pageLogicalHeight || m_columnInfo || renderer->isRenderFlowThread();
+    m_isPaginated = m_pageLogicalHeight || m_columnInfo;
 
     if (lineGrid() && renderer->hasColumns() && renderer->style()->hasInlineColumnAxis())
         computeLineGridPaginationOrigin(renderer);
 
     // If we have a new grid to track, then add it to our set.
     if (renderer->style()->lineGrid() != RenderStyle::initialLineGrid() && renderer->isRenderBlockFlow())
         establishLineGrid(toRenderBlockFlow(renderer));
 
     // FIXME: <http://bugs.webkit.org/show_bug.cgi?id=13443> Apply control clip if present.
 }
@@ skipping 132 matching lines @@
             LayoutUnit paginationDelta = gridLineHeight - remainder;
             if (isHorizontalWritingMode)
                 m_lineGridPaginationOrigin.setHeight(paginationDelta);
             else
                 m_lineGridPaginationOrigin.setWidth(paginationDelta);
         }
     }
 }
 
 } // namespace WebCore