Extension method support to move us closer to a valid List implementation.

lib/runtime/dart/async.js

Index: lib/runtime/dart/async.js
diff --git a/lib/runtime/dart/async.js b/lib/runtime/dart/async.js
index 31e448b72d84a7cbb065b712f2d4fc564a766c65..dd15656c1c9bc31d649ebaec109c5fc462bce424 100644
--- a/lib/runtime/dart/async.js
+++ b/lib/runtime/dart/async.js
@@ -375,7 +375,7 @@ var async;
         let result = new core.List$(T).from([]);
         let future = new (_Future$(core.List$(T)))();
         this.listen(((data) => {
-          result.add(data);
+          result[core.$add](data);
         }).bind(this), {onError: future[_completeError], onDone: (() => {
             future._complete(result);
           }).bind(this), cancelOnError: true});
@@ -1676,7 +1676,7 @@ var async;
           future.then(((value) => {
             remaining = dart.notNull(remaining) - 1;
             if (values != null) {
-              values.set(pos, value);
+              values[core.$set](pos, value);
               if (remaining == 0) {
                 result._completeWithValue(values);
               }
@@ -1699,7 +1699,7 @@ var async;
         return result;
       }
       static forEach(input, f) {
-        let iterator = input.iterator;
+        let iterator = input[core.$iterator];
         return Future.doWhile((() => {
           if (!dart.notNull(iterator.moveNext()))
             return false;
@@ -3111,7 +3111,7 @@ var async;
   let _IterablePendingEvents$ = dart.generic(function(T) {
     class _IterablePendingEvents extends _PendingEvents {
       _IterablePendingEvents(data) {
-        this[_iterator] = data.iterator;
+        this[_iterator] = data[core.$iterator];
         super._PendingEvents();
       }
       get isEmpty() {