Remove more scrolling code from Sky

sky/engine/core/rendering/RenderLayer.h

Index: sky/engine/core/rendering/RenderLayer.h
diff --git a/sky/engine/core/rendering/RenderLayer.h b/sky/engine/core/rendering/RenderLayer.h
index bcb14400d128c9de820768273d3e0c7bb1a323ef..f51b3a2508387fe93712ee4863799194980ba5eb 100644
--- a/sky/engine/core/rendering/RenderLayer.h
+++ b/sky/engine/core/rendering/RenderLayer.h
@@ -239,8 +239,6 @@ public:
 
     Node* enclosingElement() const;
 
-    bool scrollsWithRespectTo(const RenderLayer*) const;
-
     RenderLayerClipper& clipper() { return m_clipper; }
     const RenderLayerClipper& clipper() const { return m_clipper; }
 
@@ -258,8 +256,6 @@ public:
             , transformAncestor(0)
             , filterAncestor(0)
             , clippingContainer(0)
-            , ancestorScrollingLayer(0)
-            , scrollParent(0)
             , clipParent(0)
             , isUnclippedDescendant(false)
             , hasAncestorWithClipPath(false)
@@ -270,15 +266,6 @@ public:
         const RenderLayer* transformAncestor;
         const RenderLayer* filterAncestor;
         const RenderObject* clippingContainer;
-        const RenderLayer* ancestorScrollingLayer;
-
-        // A scroll parent is a compositor concept. It's only needed in blink
-        // because we need to use it as a promotion trigger. A layer has a
-        // scroll parent if neither its compositor scrolling ancestor, nor any
-        // other layer scrolled by this ancestor, is a stacking ancestor of this
-        // layer. Layers with scroll parents must be scrolled with the main
-        // scrolling layer by the compositor.
-        const RenderLayer* scrollParent;
 
         // A clip parent is another compositor concept that has leaked into
         // blink so that it may be used as a promotion trigger. Layers with clip
@@ -332,8 +319,6 @@ public:
     const RenderLayer* transformAncestor() const { return ancestorDependentCompositingInputs().transformAncestor; }
     const RenderLayer* filterAncestor() const { return ancestorDependentCompositingInputs().filterAncestor; }
     const RenderObject* clippingContainer() const { return ancestorDependentCompositingInputs().clippingContainer; }
-    const RenderLayer* ancestorScrollingLayer() const { return ancestorDependentCompositingInputs().ancestorScrollingLayer; }
-    RenderLayer* scrollParent() const { return const_cast<RenderLayer*>(ancestorDependentCompositingInputs().scrollParent); }
     RenderLayer* clipParent() const { return const_cast<RenderLayer*>(ancestorDependentCompositingInputs().clipParent); }
     bool isUnclippedDescendant() const { return ancestorDependentCompositingInputs().isUnclippedDescendant; }
     bool hasAncestorWithClipPath() const { return ancestorDependentCompositingInputs().hasAncestorWithClipPath; }