Add support for capturing and changing the current isolate in the closure wrapper.

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 171 matching lines @@
     if (enabledNoSuchMethod) return;
     if (element.enclosingElement == objectClass) return;
     enabledNoSuchMethod = true;
     Set<Invocation> invocations = universe.invokedNames.putIfAbsent(
         NO_SUCH_METHOD, () => new Set<Invocation>());
     invocations.add(new Invocation(2));
   }
 
   void enableIsolateSupport(LibraryElement element) {
     isolateLibrary = element;
-    addToWorkList(element.find(START_ROOT_ISOLATE)); 
+    addToWorkList(element.find(START_ROOT_ISOLATE));
   }
 
+  bool hasIsolateSupport() => isolateLibrary !== null;
+
   void onLibraryLoaded(LibraryElement library, Uri uri) {
     if (uri.toString() == 'dart:isolate') {
       enableIsolateSupport(library);
     }
   }
 
   abstract LibraryElement scanBuiltinLibrary(String filename);
 
   void scanBuiltinLibraries() {
     coreImplLibrary = scanBuiltinLibrary('coreimpl.dart');
@@ skipping 16 matching lines @@
   }
 
   /** Define the JS helper functions in the given library. */
   void addForeignFunctions(LibraryElement library) {
     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);
   }
 
   void runCompiler(Uri uri) {
     scanBuiltinLibraries();
     mainApp = scanner.loadLibrary(uri, null);
     Element element;
     withCurrentElement(mainApp, () {
       element = mainApp.find(MAIN);
       if (element === null) cancel('Could not find $MAIN');
     });
@@ skipping 234 matching lines @@
   }
 }
 
 class SourceSpan {
   final Uri uri;
   final int begin;
   final int end;
 
   const SourceSpan(this.uri, this.begin, this.end);
 }