Only create sticky position constraints for constrained sticky position.

third_party/WebKit/Source/core/layout/compositing/CompositedLayerMapping.cpp

 /*
  * Copyright (C) 2009, 2010, 2011 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 276 matching lines @@
 }
 
 void CompositedLayerMapping::updateBackdropFilters(const ComputedStyle& style) {
   m_graphicsLayer->setBackdropFilters(
       owningLayer().createCompositorFilterOperationsForBackdropFilter(style));
 }
 
 void CompositedLayerMapping::updateStickyConstraints(
     const ComputedStyle& style,
     const PaintLayer* compositingContainer) {
-  bool sticky = style.position() == EPosition::kSticky;
+  bool sticky = style.hasStickyConstrainedPosition();
   const PaintLayer* ancestorOverflowLayer =
       m_owningLayer.ancestorOverflowLayer();
   // TODO(flackr): Do we still need this?
   if (sticky) {
     if (!ancestorOverflowLayer->isRootLayer()) {
       sticky = ancestorOverflowLayer->needsCompositedScrolling();
     } else {
       sticky = layoutObject().view()->frameView()->isScrollable();
     }
   }
@@ skipping 3190 matching lines @@
   } else if (graphicsLayer == m_decorationOutlineLayer.get()) {
     name = "Decoration Layer";
   } else {
     ASSERT_NOT_REACHED();
   }
 
   return name;
 }
 
 }  // namespace blink