Progress converting to new error system
diff --git a/src/core/lib/support/avl.c b/src/core/lib/support/avl.c
index 8d3ce23..ceded9d 100644
--- a/src/core/lib/support/avl.c
+++ b/src/core/lib/support/avl.c
@@ -286,3 +286,5 @@
 }
 
 void gpr_avl_unref(gpr_avl avl) { unref_node(avl.vtable, avl.root); }
+
+int gpr_avl_is_empty(gpr_avl avl) { return avl.root == NULL; }