Add ClipNode when Render Surface Inherits Clip

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 8ad44070ec7ffdf6d648c6356e6673153b9366d3..cf628fa6ad4f322d96ef601352bfdd6766ce65bc 100644
--- a/cc/trees/property_tree_builder.cc
+++ b/cc/trees/property_tree_builder.cc
@@ -79,6 +79,9 @@ static bool RequiresClipNode(LayerType* layer,
   if (!render_surface_applies_clip)
     return false;
 
+  if (layer->parent())
+    return true;
+
   bool axis_aligned_with_respect_to_parent =

[ajuma, 2015/08/05 13:51:09]

Will this ever be true now? If we reach this point, we're at the root layer,
which can't be non-axis aligned.

[jaydasika, 2015/08/05 15:07:20]

Done.

       data.transform_tree->Are2DAxisAligned(layer->transform_tree_index(),
                                             parent_transform_id);
@@ -105,6 +108,7 @@ void AddClipNodeIfNeeded(const DataForRecursion<LayerType>& data_from_ancestor,
 
   data_for_children->ancestor_clips_subtree = false;
   bool has_unclipped_surface = false;
+  bool use_clip_parent_for_layer = false;
 
   if (layer->has_render_surface()) {
     if (ancestor_clips_subtree && layer->num_unclipped_descendants() > 0)
@@ -122,7 +126,7 @@ void AddClipNodeIfNeeded(const DataForRecursion<LayerType>& data_from_ancestor,
     parent_id = 0;
 
   if (!RequiresClipNode(layer, data_from_ancestor, parent->data.transform_id,
-                        data_for_children->ancestor_clips_subtree)) {
+                        ancestor_clips_subtree)) {
     // Unclipped surfaces reset the clip rect.
     data_for_children->clip_tree_parent = parent_id;
   } else {
@@ -138,13 +142,19 @@ void AddClipNodeIfNeeded(const DataForRecursion<LayerType>& data_from_ancestor,
     node.data.target_id =
         data_for_children->render_target->transform_tree_index();
     node.owner_id = layer->id();
-
+    node.data.inherit_parent_target_space_clip =
+        !data_for_children->ancestor_clips_subtree &&
+        layer->has_render_surface() && ancestor_clips_subtree;
+    if (node.data.inherit_parent_target_space_clip)
+      use_clip_parent_for_layer = true;
     data_for_children->clip_tree_parent =
         data_for_children->clip_tree->Insert(node, parent_id);
   }
 
   layer->SetClipTreeIndex(
       has_unclipped_surface ? 0 : data_for_children->clip_tree_parent);
+  if (use_clip_parent_for_layer)
+    layer->SetClipTreeIndex(data_from_ancestor.clip_tree_parent);
 
   layer->set_is_clipped(data_for_children->ancestor_clips_subtree);