Handle dart:html in kernel_impact

pkg/compiler/lib/src/native/behavior.dart

 // Copyright (c) 2014, 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.
 
 import '../common.dart';
 import '../common/backend_api.dart' show ForeignResolver;
 import '../common/resolution.dart' show ParsingContext, Resolution;
 import '../compiler.dart' show Compiler;
 import '../constants/expressions.dart';
 import '../constants/values.dart';
@@ skipping 13 matching lines @@
 /// This class is a temporary work-around until we get a more powerful DartType.
 class SpecialType {
   final String name;
   const SpecialType._(this.name);
 
   /// The type Object, but no subtypes:
   static const JsObject = const SpecialType._('=Object');
 
   int get hashCode => name.hashCode;
 
+  String toString() => name;
+
   static SpecialType fromName(String name) {
     if (name == '=Object') {
       return JsObject;
     } else {
       throw new UnsupportedError("Unknown SpecialType '$name'.");
     }
   }
 }
 
 /// Description of the exception behaviour of native code.
@@ skipping 956 matching lines @@
     type = lookupType(typeString.substring(0, index));
     if (type != null) {
       // TODO(sra): Parse type parameters.
       return type;
     }
     reporter.reportErrorMessage(spannable, MessageKind.GENERIC,
         {'text': "Type '$typeString' not found."});
     return const DynamicType();
   }
 }