initial sync*, part of #221

lib/runtime/dart/js.js

Index: lib/runtime/dart/js.js
diff --git a/lib/runtime/dart/js.js b/lib/runtime/dart/js.js
index ca0b38c1828283ab57051affeb90e1a5fbe5aa03..820404e29f5f91ef6eec73ab527d60083c814fe7 100644
--- a/lib/runtime/dart/js.js
+++ b/lib/runtime/dart/js.js
@@ -16,11 +16,11 @@ dart_library.library('dart/js', null, /* Imports */[
   });
   function _convertDartFunction(f, opts) {
     let captureThis = opts && 'captureThis' in opts ? opts.captureThis : false;
-    return function(_call, f, captureThis) {
+    return (function(_call, f, captureThis) {
       return function() {
         return _call(f, captureThis, this, Array.prototype.slice.apply(arguments));
       };
-    }(_foreign_helper.DART_CLOSURE_TO_JS(_callDartFunction), f, captureThis);
+    })(_foreign_helper.DART_CLOSURE_TO_JS(_callDartFunction), f, captureThis);
   }
   dart.fn(_convertDartFunction, dart.dynamic, [core.Function], {captureThis: core.bool});
   function _callDartFunction(callback, captureThis, self, arguments$) {
@@ -67,7 +67,7 @@ dart_library.library('dart/js', null, /* Imports */[
     }
     static _convertDataTree(data) {
       let _convertedObjects = collection.HashMap.identity();
-      let _convert = o => {
+      function _convert(o) {
         if (dart.notNull(_convertedObjects.containsKey(o))) {
           return _convertedObjects.get(o);
         }
@@ -86,7 +86,7 @@ dart_library.library('dart/js', null, /* Imports */[
         } else {
           return _convertToJS(o);
         }
-      };
+      }
       dart.fn(_convert);
       return _convert(data);
     }