cc : Stop pushing layers from hidden subtrees at commit

cc/trees/layer_tree_impl.h

Index: cc/trees/layer_tree_impl.h
diff --git a/cc/trees/layer_tree_impl.h b/cc/trees/layer_tree_impl.h
index 46f57fda5b625c775e9c8d0bb1647948137ce6c7..e1db09227de28ade6ed025e803d89c906a7a059f 100644
--- a/cc/trees/layer_tree_impl.h
+++ b/cc/trees/layer_tree_impl.h
@@ -359,6 +359,11 @@ class CC_EXPORT LayerTreeImpl {
   void AddToElementMap(LayerImpl* layer);
   void RemoveFromElementMap(LayerImpl* layer);
 
+  using SurfaceIdsList = std::vector<const SurfaceId*>;
+  void SetHiddenSurfaceLayerIds(const SurfaceIdsList* hidden_surface_layer_ids);
+  const SurfaceIdsList* HiddenSurfaceLayerIds() const;
+  void ClearHiddenSurfaceLayerIds();
+
   void AddLayerShouldPushProperties(LayerImpl* layer);
   void RemoveLayerShouldPushProperties(LayerImpl* layer);
   std::unordered_set<LayerImpl*>& LayersThatShouldPushProperties();
@@ -586,6 +591,8 @@ class CC_EXPORT LayerTreeImpl {
   // is a pair of scrollbar layer ids instead of using a multimap.
   std::multimap<ElementId, int> element_id_to_scrollbar_layer_ids_;
 
+  SurfaceIdsList hidden_surface_layer_ids_;
+
   std::vector<PictureLayerImpl*> picture_layers_;
   LayerImplList surface_layers_;