Remove support for interface in dart2js.

sdk/lib/_internal/compiler/implementation/tree/nodes.dart

Index: sdk/lib/_internal/compiler/implementation/tree/nodes.dart
diff --git a/sdk/lib/_internal/compiler/implementation/tree/nodes.dart b/sdk/lib/_internal/compiler/implementation/tree/nodes.dart
index 604ef462f7c4b4741371755d9c754b08464c936e..118996b83a7dd5c398d9c5df2650e560b9a5dc5d 100644
--- a/sdk/lib/_internal/compiler/implementation/tree/nodes.dart
+++ b/sdk/lib/_internal/compiler/implementation/tree/nodes.dart
@@ -213,15 +213,12 @@ class ClassNode extends Node {
   final NodeList typeParameters;
   final NodeList body;
 
-  // TODO(ahe, karlklose): the default keyword is not recorded.
-  final TypeAnnotation defaultClause;
-
   final Token beginToken;
   final Token extendsKeyword;
   final Token endToken;
 
   ClassNode(this.modifiers, this.name, this.typeParameters, this.superclass,
-            this.interfaces, this.defaultClause, this.beginToken,
+            this.interfaces, this.beginToken,
             this.extendsKeyword, this.body, this.endToken);
 
   ClassNode asClassNode() => this;