Unify the calculation of main thread offset of sticky element

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

 /*
  * 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 350 matching lines @@
       const IntRect& relative_compositing_bounds);
   void UpdateForegroundLayerGeometry(
       const FloatSize& relative_compositing_bounds_size,
       const IntRect& clipping_box);
   void UpdateBackgroundLayerGeometry(
       const FloatSize& relative_compositing_bounds_size);
   void UpdateDecorationOutlineLayerGeometry(
       const FloatSize& relative_compositing_bounds_size);
   void UpdateScrollingLayerGeometry(const IntRect& local_compositing_bounds);
   void UpdateChildClippingMaskLayerGeometry();
-  void UpdateStickyConstraints(const ComputedStyle&, const PaintLayer*);
+  void UpdateStickyConstraints(const ComputedStyle&);
 
   void CreatePrimaryGraphicsLayer();
   void DestroyGraphicsLayers();
 
   std::unique_ptr<GraphicsLayer> CreateGraphicsLayer(
       CompositingReasons,
       SquashingDisallowedReasons = kSquashingDisallowedReasonsNone);
   bool ToggleScrollbarLayerIfNeeded(std::unique_ptr<GraphicsLayer>&,
                                     bool needs_layer,
                                     CompositingReasons);
@@ skipping 325 matching lines @@
   unsigned background_paints_onto_graphics_layer_ : 1;
 
   bool draws_background_onto_content_layer_;
 
   friend class CompositedLayerMappingTest;
 };
 
 }  // namespace blink
 
 #endif  // CompositedLayerMapping_h