Cleanup references to the old DDC repo

pkg/dev_compiler/tool/input_sdk/private/js_helper.dart

 // Copyright (c) 2013, 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.
 
 library dart._js_helper;
 
 import 'dart:collection';
 
 import 'dart:_foreign_helper' show
     JS,
@@ skipping 860 matching lines @@
   int int32a = JS("int", "(Math.random() * 0x100000000) >>> 0");
   int int32b = JS("int", "(Math.random() * 0x100000000) >>> 0");
   return int32a + int32b * 0x100000000;
 }
 
 String jsonEncodeNative(String string) {
   return JS("String", "JSON.stringify(#)", string);
 }
 
 
-// TODO(jmesserly): this adapter is to work around:
-// https://github.com/dart-lang/dev_compiler/issues/247
+// TODO(jmesserly): this adapter is to work around
+// https://github.com/dart-lang/sdk/issues/28320
 class SyncIterator<E> implements Iterator<E> {
   final dynamic _jsIterator;
   E _current;
 
   SyncIterator(this._jsIterator);
 
   E get current => _current;
 
   bool moveNext() {
     final ret = JS('', '#.next()', _jsIterator);
@@ skipping 12 matching lines @@
   // we have no way of telling the compiler yet, so it will generate an extra
   // layer of indirection that wraps the SyncIterator.
   _jsIterator() => JS('', '#(...#)', _generator, _args);
 
   Iterator<E> get iterator => new SyncIterator<E>(_jsIterator());
 }
 
 class BooleanConversionAssertionError extends AssertionError {
   toString() => 'Failed assertion: boolean expression must not be null';
 }