Add ConstantExpression.evaluate.

pkg/compiler/lib/src/js_backend/constant_handler_javascript.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.
 
 part of js_backend;
 
 /// [ConstantCompilerTask] for compilation of constants for the JavaScript
 /// backend.
 ///
 /// Since this task needs to distinguish between frontend and backend constants
@@ skipping 185 matching lines @@
 
   ConstantExpression compileMetadata(MetadataAnnotation metadata,
                            Node node,
                            TreeElements elements) {
     ConstantExpression constant =
         super.compileMetadata(metadata, node, elements);
     metadataConstantMap[metadata] = constant;
     return constant;
   }
 
-  ConstantExpression createTypeConstant(TypeDeclarationElement element) {
-    DartType elementType = element.rawType;
-    DartType constantType =
-        compiler.backend.typeImplementation.computeType(compiler);
-    return new TypeConstantExpression(
-        new TypeConstantValue(elementType, constantType), elementType);
-  }
-
   void forgetElement(Element element) {
     super.forgetElement(element);
     const ForgetConstantElementVisitor().visit(element, this);
     if (element is AstElement && element.hasNode) {
       element.node.accept(new ForgetConstantNodeVisitor(this));
     }
   }
 }
 
 class ForgetConstantElementVisitor
@@ skipping 30 matching lines @@
     // TODO(ahe): This doesn't belong here. Rename this class and generalize.
     var closureClassMap =
         constants.compiler.closureToClassMapper.closureMappingCache
         .remove(node);
     if (closureClassMap != null) {
       closureClassMap.removeMyselfFrom(
           constants.compiler.enqueuer.codegen.universe);
     }
   }
 }