| Index: pkg/dev_compiler/lib/js/legacy/dart_sdk.js | 
| diff --git a/pkg/dev_compiler/lib/js/legacy/dart_sdk.js b/pkg/dev_compiler/lib/js/legacy/dart_sdk.js | 
| index 2b9490006585a396794c4312ae12990484910e0d..cf152c40d3030c101d8d4555c098cd9618a3718a 100644 | 
| --- a/pkg/dev_compiler/lib/js/legacy/dart_sdk.js | 
| +++ b/pkg/dev_compiler/lib/js/legacy/dart_sdk.js | 
| @@ -1907,7 +1907,7 @@ dart_library.library('dart_sdk', null, /* Imports */[ | 
| } | 
| return future.then(dart.dynamic)(onValue, {onError: onError}); | 
| } | 
| -    return dart.getGenericClass(async.Future)(T).new(function() { | 
| +    return dart.getGenericClass(async.Future)(T).microtask(function() { | 
| iter = gen.apply(null, args)[Symbol.iterator](); | 
| return onValue(); | 
| }); | 
|  |