support class native clause

pkg/front_end/lib/src/fasta/source/outline_builder.dart

 // Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library fasta.outline_builder;
 
 import 'package:kernel/ast.dart' show ProcedureKind;
 
 import '../../scanner/token.dart' show Token;
 
@@ skipping 275 matching lines @@
   void beginClassDeclaration(Token begin, Token name) {
     library.currentDeclaration.name = name.lexeme;
   }
 
   @override
   void beginNamedMixinApplication(Token beginToken, Token name) {
     library.currentDeclaration.name = name.lexeme;
   }
 
   @override
+  void handleNativeClause(Token nativeToken, bool hasName) {
+    if (hasName) {
+      // Pop the native clause which in this case is a StringLiteral.
+      pop(); // Char offset.
+      pop(); // String.
+    }
+  }
+
+  @override
   void endClassDeclaration(
       int interfacesCount,
       Token beginToken,
       Token classKeyword,
       Token extendsKeyword,
       Token implementsKeyword,
+      Token nativeToken,
       Token endToken) {
     debugEvent("endClassDeclaration");
     String documentationComment = _getDocumentationComment(beginToken);
     List<TypeBuilder> interfaces = popList(interfacesCount);
     TypeBuilder supertype = pop();
     List<TypeVariableBuilder> typeVariables = pop();
     int charOffset = pop();
     String name = pop();
     if (typeVariables != null && supertype is MixinApplicationBuilder) {
       supertype.typeVariables = typeVariables;
@@ skipping 652 matching lines @@
       docToken = docToken.next;
     }
     return buffer.toString();
   }
 
   @override
   void debugEvent(String name) {
     // printEvent(name);
   }
 }