Remove support for interface in dart2js.

sdk/lib/_internal/compiler/implementation/tools/mini_parser.dart

Index: sdk/lib/_internal/compiler/implementation/tools/mini_parser.dart
diff --git a/sdk/lib/_internal/compiler/implementation/tools/mini_parser.dart b/sdk/lib/_internal/compiler/implementation/tools/mini_parser.dart
index 17578d5abaf630b7073505b4cd8a56a6c415b2af..ba3f01db1b7efa1f0beeb5c93f28e295f9a33472 100644
--- a/sdk/lib/_internal/compiler/implementation/tools/mini_parser.dart
+++ b/sdk/lib/_internal/compiler/implementation/tools/mini_parser.dart
@@ -229,13 +229,6 @@ class MyNodeListener extends NodeListener {
     ClassNode node = popNode(); // Discard ClassNode and assert the type.
   }
 
-  void endInterface(int supertypeCount, Token interfaceKeyword,
-                    Token extendsKeyword, Token endToken) {
-    super.endInterface(supertypeCount, interfaceKeyword, extendsKeyword,
-                       endToken);
-    ClassNode node = popNode(); // Discard ClassNode and assert the type.
-  }
-
   void endTopLevelFields(int count, Token beginToken, Token endToken) {
     super.endTopLevelFields(count, beginToken, endToken);
     VariableDefinitions node = popNode(); // Discard node and assert the type.