Adapt and reland old position sticky implementation

Source/core/paint/DeprecatedPaintLayer.h

Index: Source/core/paint/DeprecatedPaintLayer.h
diff --git a/Source/core/paint/DeprecatedPaintLayer.h b/Source/core/paint/DeprecatedPaintLayer.h
index f997d76316ba810b8dd2830376e9790ed694453c..0e305e314c5f097cd30cbe07b4ee91d60d468848 100644
--- a/Source/core/paint/DeprecatedPaintLayer.h
+++ b/Source/core/paint/DeprecatedPaintLayer.h
@@ -390,6 +390,7 @@ public:
     Node* enclosingElement() const;
 
     bool scrollsWithViewport() const;
+    bool scrollsWithScrollAncestor() const;
     bool scrollsWithRespectTo(const DeprecatedPaintLayer*) const;
 
     void addLayerHitTestRects(LayerHitTestRects&) const;
@@ -485,7 +486,13 @@ public:
     void updateDescendantDependentCompositingInputs(const DescendantDependentCompositingInputs&);
     void didUpdateCompositingInputs();
 
-    const AncestorDependentCompositingInputs& ancestorDependentCompositingInputs() const { ASSERT(!m_needsAncestorDependentCompositingInputsUpdate); return m_ancestorDependentCompositingInputs; }
+    const AncestorDependentCompositingInputs& ancestorDependentCompositingInputs() const
+    {
+        // TODO(flackr): When we process scroll updates after compositing updates we won't be querying ancestor
+        // dependent compositing inputs while they're still needed: http://crbug.com/420741.
+        ASSERT(isAllowedToQueryCompositingState() || !m_needsAncestorDependentCompositingInputsUpdate);
+        return m_ancestorDependentCompositingInputs;
+    }
     const DescendantDependentCompositingInputs& descendantDependentCompositingInputs() const { ASSERT(!m_needsDescendantDependentCompositingInputsUpdate); return m_descendantDependentCompositingInputs; }
 
     IntRect clippedAbsoluteBoundingBox() const { return ancestorDependentCompositingInputs().clippedAbsoluteBoundingBox; }