Compute if a layer is clipped outside CalcDrawProps

cc/trees/property_tree_builder.cc

Index: cc/trees/property_tree_builder.cc
diff --git a/cc/trees/property_tree_builder.cc b/cc/trees/property_tree_builder.cc
index 28ad43f309111ac26e9eb433bc3e5acaf11f6500..606a2af20e17cf13ca8157f016b7b2ab0723782b 100644
--- a/cc/trees/property_tree_builder.cc
+++ b/cc/trees/property_tree_builder.cc
@@ -145,6 +145,12 @@ void AddClipNodeIfNeeded(const DataForRecursion<LayerType>& data_from_ancestor,
   layer->SetClipTreeIndex(
       has_unclipped_surface ? 0 : data_for_children->clip_tree_parent);
 
+  // TODO(jaydasika): This value depends on whether a layer has a render
+  // surface or not. When building property trees becomes independant of
+  // render surfaces(see http://crbug.com/504467), this should move.

[Ian Vollick, 2015/07/07 19:09:39]

Hey, I wanted to mention here what we'd discussed offline -- that constructing
clip trees (unlike transform trees) will likely come after layerization and
render surface determination. I've made a comment on the liked bug. This second
sentence should probably be ditched?

[jaydasika, 2015/07/07 19:15:56]

If render surfaces are determined before building clip tree, the whole comment
can be ditched as we don't need to move is_clipped computation 

+  layer->set_is_clipped_from_property_tree(
+      data_for_children->ancestor_clips_subtree);
+
   // TODO(awoloszyn): Right now when we hit a node with a replica, we reset the
   // clip for all children since we may need to draw. We need to figure out a
   // better way, since we will need both the clipped and unclipped versions.