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

Source/core/rendering/RootInlineBox.cpp

Index: Source/core/rendering/RootInlineBox.cpp
diff --git a/Source/core/rendering/RootInlineBox.cpp b/Source/core/rendering/RootInlineBox.cpp
index 0d95cafe0447ab41f6310ad8046df058f3318654..f166db4c43167769afd0245a6f00743b18cd7d86 100644
--- a/Source/core/rendering/RootInlineBox.cpp
+++ b/Source/core/rendering/RootInlineBox.cpp
@@ -26,7 +26,6 @@
 #include "core/rendering/InlineTextBox.h"
 #include "core/rendering/PaintInfo.h"
 #include "core/rendering/RenderBlockFlow.h"
-#include "core/rendering/RenderFlowThread.h"
 #include "core/rendering/RenderInline.h"
 #include "core/rendering/RenderView.h"
 #include "core/rendering/VerticalPositionCache.h"
@@ -209,29 +208,6 @@ void RootInlineBox::childRemoved(InlineBox* box)
     }
 }
 
-RenderRegion* RootInlineBox::containingRegion() const
-{
-    RenderRegion* region = m_fragmentationData ? m_fragmentationData->m_containingRegion : 0;
-
-#ifndef NDEBUG
-    if (region) {
-        RenderFlowThread* flowThread = block()->flowThreadContainingBlock();
-        const RenderRegionList& regionList = flowThread->renderRegionList();
-        ASSERT(regionList.contains(region));
-    }
-#endif
-
-    return region;
-}
-
-void RootInlineBox::setContainingRegion(RenderRegion* region)
-{
-    ASSERT(!isDirty());
-    ASSERT(block()->flowThreadContainingBlock());
-    LineFragmentationData* fragmentationData  = ensureLineFragmentationData();
-    fragmentationData->m_containingRegion = region;
-}
-
 LayoutUnit RootInlineBox::alignBoxesInBlockDirection(LayoutUnit heightOfBlock, GlyphOverflowAndFallbackFontsMap& textBoxDataMap, VerticalPositionCache& verticalPositionCache)
 {
     // SVG will handle vertical alignment on its own.
@@ -272,7 +248,7 @@ LayoutUnit RootInlineBox::alignBoxesInBlockDirection(LayoutUnit heightOfBlock, G
     maxHeight = max<LayoutUnit>(0, maxHeight); // FIXME: Is this really necessary?
 
     setLineTopBottomPositions(lineTop, lineBottom, heightOfBlock, heightOfBlock + maxHeight);
-    setPaginatedLineWidth(block()->availableLogicalWidthForContent(heightOfBlock));
+    setPaginatedLineWidth(block()->availableLogicalWidthForContent());
 
     LayoutUnit annotationsAdjustment = beforeAnnotationsAdjustment();
     if (annotationsAdjustment) {