Write our JS blobs for handling native classes in Dart.

frog/leg/compiler.dart

 // Copyright (c) 2012, 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.
 
 class WorkItem {
   final Element element;
   TreeElements resolutionTree;
   Function run;
   Map<int, BailoutInfo> bailouts = null;
   bool allowSpeculativeOptimization = true;
@@ skipping 247 matching lines @@
     library.define(new ForeignElement(
         const SourceString('JS'), library), this);
     library.define(new ForeignElement(
         const SourceString('UNINTERCEPTED'), library), this);
     library.define(new ForeignElement(
         const SourceString('JS_HAS_EQUALS'), library), this);
     library.define(new ForeignElement(
         const SourceString('JS_CURRENT_ISOLATE'), library), this);
     library.define(new ForeignElement(
         const SourceString('JS_CALL_IN_ISOLATE'), library), this);
+    library.define(new ForeignElement(
+        const SourceString('DART_CLOSURE_TO_JS'), library), this);
   }
 
   void runCompiler(Uri uri) {
     scanBuiltinLibraries();
     mainApp = scanner.loadLibrary(uri, null);
     final Element mainMethod = mainApp.find(MAIN);
     if (mainMethod === null) {
       withCurrentElement(mainApp, () => cancel('Could not find $MAIN'));
     } else {
       withCurrentElement(mainMethod, () {
@@ skipping 258 matching lines @@
   }
 }
 
 class SourceSpan {
   final Uri uri;
   final int begin;
   final int end;
 
   const SourceSpan(this.uri, this.begin, this.end);
 }