Refactor scroll chaining to use ScrollNodes without going through LayerImpl

cc/layers/layer_impl.h

 // Copyright 2011 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_LAYERS_LAYER_IMPL_H_
 #define CC_LAYERS_LAYER_IMPL_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 41 matching lines @@
 namespace cc {
 
 class LayerTreeImpl;
 class MicroBenchmarkImpl;
 class MutatorHost;
 class PrioritizedTile;
 class RenderPass;
 class ScrollbarLayerImplBase;
 class SimpleEnclosedRegion;
 class Tile;
-class ScrollState;
 
 struct AppendQuadsData;
 
 enum DrawMode {
   DRAW_MODE_NONE,
   DRAW_MODE_HARDWARE,
   DRAW_MODE_SOFTWARE,
   DRAW_MODE_RESOURCELESS_SOFTWARE
 };
 
@@ skipping 10 matching lines @@
   virtual ~LayerImpl();
 
   int id() const { return layer_id_; }
 
   // Interactions with attached animations.
   gfx::ScrollOffset ScrollOffsetForAnimation() const;
   void OnIsAnimatingChanged(const PropertyAnimationState& mask,
                             const PropertyAnimationState& state);
   bool IsActive() const;
 
-  void DistributeScroll(ScrollState* scroll_state);
-
   void set_property_tree_sequence_number(int sequence_number) {}
 
   void SetTransformTreeIndex(int index);
   int transform_tree_index() const { return transform_tree_index_; }
 
   void SetClipTreeIndex(int index);
   int clip_tree_index() const { return clip_tree_index_; }
 
   void SetEffectTreeIndex(int index);
   int effect_tree_index() const { return effect_tree_index_; }
@@ skipping 473 matching lines @@
   bool has_will_change_transform_hint_ : 1;
   bool needs_push_properties_ : 1;
   bool scrollbars_hidden_ : 1;
 
   DISALLOW_COPY_AND_ASSIGN(LayerImpl);
 };
 
 }  // namespace cc
 
 #endif  // CC_LAYERS_LAYER_IMPL_H_