Handle nested position:sticky elements correctly (compositor)

cc/trees/draw_property_utils.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CC_TREES_DRAW_PROPERTY_UTILS_H_
 #define CC_TREES_DRAW_PROPERTY_UTILS_H_
 
 #include "cc/base/cc_export.h"
 #include "cc/layers/layer_collections.h"
 
@@ skipping 116 matching lines @@
 void CC_EXPORT
 UpdateElasticOverscroll(PropertyTrees* property_trees,
                         const LayerImpl* overscroll_elasticity_layer,
                         const gfx::Vector2dF& elastic_overscroll);
 
 void CC_EXPORT
 UpdateElasticOverscroll(PropertyTrees* property_trees,
                         const Layer* overscroll_elasticity_layer,
                         const gfx::Vector2dF& elastic_overscroll);
 
+gfx::Vector2dF CC_EXPORT
+CalculateTotalStickyOffsetToScroller(Layer* layer,
+                                     int scroll_ancestor_layer_id);
+
 }  // namespace draw_property_utils
 }  // namespace cc
 
 #endif  // CC_TREES_DRAW_PROPERTY_UTILS_H_