Remove the Pagination struct, clean up viewport scroll policy propagation.

Source/core/rendering/style/RenderStyle.h

Index: Source/core/rendering/style/RenderStyle.h
diff --git a/Source/core/rendering/style/RenderStyle.h b/Source/core/rendering/style/RenderStyle.h
index 9e42ffe6d9fd9c5be04be13b361c8333e6ba0b1f..75f8a3e28e9392eb9ca25b18bd1bac69e907bf6b 100644
--- a/Source/core/rendering/style/RenderStyle.h
+++ b/Source/core/rendering/style/RenderStyle.h
@@ -538,6 +538,7 @@ public:
     EOverflow overflowY() const { return static_cast<EOverflow>(noninherited_flags._overflowY); }
     // It's sufficient to just check one direction, since it's illegal to have visible on only one overflow value.
     bool isOverflowVisible() const { ASSERT(overflowX() != OVISIBLE || overflowX() == overflowY()); return overflowX() == OVISIBLE; }
+    bool isOverflowPaged() const { return overflowY() == OPAGEDX || overflowY() == OPAGEDY; }
 
     EVisibility visibility() const { return static_cast<EVisibility>(inherited_flags._visibility); }
     EVerticalAlign verticalAlign() const { return static_cast<EVerticalAlign>(noninherited_flags._vertical_align); }
@@ -829,6 +830,15 @@ public:
         ColumnAxis axis = columnAxis();
         return axis == AutoColumnAxis || isHorizontalWritingMode() == (axis == HorizontalColumnAxis);
     }
+    bool hasInlinePaginationAxis() const
+    {
+        // If the pagination axis is parallel with the writing mode inline axis, columns may be laid
+        // out along the inline axis, just like for regular multicol. Otherwise, we need to lay out
+        // along the block axis.
+        if (isOverflowPaged())
+            return (overflowY() == OPAGEDX) == isHorizontalWritingMode();
+        return false;
+    }
     ColumnProgression columnProgression() const { return static_cast<ColumnProgression>(rareNonInheritedData->m_multiCol->m_progression); }
     float columnWidth() const { return rareNonInheritedData->m_multiCol->m_width; }
     bool hasAutoColumnWidth() const { return rareNonInheritedData->m_multiCol->m_autoWidth; }