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..ed1c0c8ca6a82e959bbf9c5c48ac59117a624544 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); }