Use ClassEntity in ClassHierarchyNode

pkg/compiler/lib/src/universe/element_world_builder.dart

Index: pkg/compiler/lib/src/universe/element_world_builder.dart
diff --git a/pkg/compiler/lib/src/universe/element_world_builder.dart b/pkg/compiler/lib/src/universe/element_world_builder.dart
index ba2b6231be3a3b88a02396e2158902bc188b35b8..f85c24f32dcd06fc3ead2f2d77bc071fdb06c7af 100644
--- a/pkg/compiler/lib/src/universe/element_world_builder.dart
+++ b/pkg/compiler/lib/src/universe/element_world_builder.dart
@@ -129,7 +129,7 @@ class ElementResolutionWorldBuilder extends ResolutionWorldBuilderBase {
       if (cls.superclass != null) {
         parentNode = _ensureClassHierarchyNode(cls.superclass);
       }
-      return new ClassHierarchyNode(parentNode, cls);
+      return new ClassHierarchyNode(parentNode, cls, cls.hierarchyDepth);
     });
   }