cc: Move main thread hierarchy dependencies into PropertyTreeBuilder

cc/trees/draw_property_utils.cc

Index: cc/trees/draw_property_utils.cc
diff --git a/cc/trees/draw_property_utils.cc b/cc/trees/draw_property_utils.cc
index 686711e62a98f1e3dc5389625d36622e42bda4e3..6b2ff3718a5637af290cc4ab83a8c225d3ee1fdd 100644
--- a/cc/trees/draw_property_utils.cc
+++ b/cc/trees/draw_property_utils.cc
@@ -71,10 +71,9 @@ static void ValidateRenderSurfaceForLayer(LayerType* layer) {
   ValidateIsNotRootForIsolatedGroup(layer);
 }
 
-static void ValidateRenderSurfacesRecursive(Layer* layer) {
-  ValidateRenderSurfaceForLayer(layer);
-  for (size_t i = 0; i < layer->children().size(); ++i)
-    ValidateRenderSurfacesRecursive(layer->child_at(i));
+static void ValidateRenderSurfacesRecursive(Layer* root_layer) {
+  for (auto* layer : *root_layer->layer_tree_host())
+    ValidateRenderSurfaceForLayer(layer);
 }
 #endif
 
@@ -374,12 +373,9 @@ void UpdateRenderSurfaceForLayer(EffectTree* effect_tree,
 }
 
 void UpdateRenderSurfacesForLayersRecursive(EffectTree* effect_tree,
-                                            Layer* layer) {
-  UpdateRenderSurfaceForLayer(effect_tree, true, layer);
-
-  for (size_t i = 0; i < layer->children().size(); ++i) {
-    UpdateRenderSurfacesForLayersRecursive(effect_tree, layer->child_at(i));
-  }
+                                            Layer* root_layer) {
+  for (auto* layer : *root_layer->layer_tree_host())
+    UpdateRenderSurfaceForLayer(effect_tree, true, layer);

[jaydasika, 2016/04/27 18:21:10]

This and ValidateRenderSurfacesRecursive can be deleted and we can both update
and validate in a single iteration that can go into the caller :
UpdateRenderSurfaces. (ComputeVisibleRects does the same thing for impl-side)

 }
 
 }  // namespace