Find root scroll layer at tree activation

cc/layer_tree_impl.h

 // Copyright 2012 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_LAYER_TREE_IMPL_H_
 #define CC_LAYER_TREE_IMPL_H_
 
 #include "base/hash_tables.h"
 #include "cc/layer_impl.h"
 
@@ skipping 13 matching lines @@
 class DebugRectHistory;
 class FrameRateCounter;
 class HeadsUpDisplayLayerImpl;
 class LayerTreeDebugState;
 class LayerTreeHostImpl;
 class LayerTreeImpl;
 class LayerTreeSettings;
 class OutputSurface;
 class PaintTimeCounter;
 class PinchZoomViewport;
+class Proxy;
 class ResourceProvider;
 class TileManager;
 
 class CC_EXPORT LayerTreeImpl {
  public:
   typedef std::vector<LayerImpl*> LayerList;
 
   static scoped_ptr<LayerTreeImpl> create(LayerTreeHostImpl* layer_tree_host_impl)
   {
     return make_scoped_ptr(new LayerTreeImpl(layer_tree_host_impl));
@@ skipping 39 matching lines @@
   int source_frame_number() const { return source_frame_number_; }
   void set_source_frame_number(int frame_number) {
     source_frame_number_ = frame_number;
   }
 
   HeadsUpDisplayLayerImpl* hud_layer() { return hud_layer_; }
   void set_hud_layer(HeadsUpDisplayLayerImpl* layer_impl) {
     hud_layer_ = layer_impl;
   }
 
-  LayerImpl* root_scroll_layer() { return root_scroll_layer_; }
-  const LayerImpl* root_scroll_layer() const { return root_scroll_layer_; }
-  void set_root_scroll_layer(LayerImpl* layer_impl) {
-    root_scroll_layer_ = layer_impl;
+  LayerImpl* RootScrollLayer();
+  LayerImpl* CurrentlyScrollingLayer();
+  void set_currently_scrolling_layer(LayerImpl* layer) {
+    currently_scrolling_layer_ = layer;
   }
 
-  LayerImpl* currently_scrolling_layer() { return currently_scrolling_layer_; }
-  void set_currently_scrolling_layer(LayerImpl* layer_impl) {
-    currently_scrolling_layer_ = layer_impl;
-  }
+  void ClearCurrentlyScrollingLayer();
 
   void FindRootScrollLayer();
-  void ClearCurrentlyScrollingLayer();
-
   void UpdateMaxScrollOffset();
 
   SkColor background_color() const { return background_color_; }
   void set_background_color(SkColor color) { background_color_ = color; }
 
   bool has_transparent_background() const {
     return has_transparent_background_;
   }
   void set_has_transparent_background(bool transparent) {
     has_transparent_background_ = transparent;
@@ skipping 49 matching lines @@
   LayerList render_surface_layer_list_;
 
   bool contents_textures_purged_;
 
   DISALLOW_COPY_AND_ASSIGN(LayerTreeImpl);
 };
 
 }
 
 #endif  // CC_LAYER_TREE_IMPL_H_