Remove calls to [new Future] work around issue 11911.

sdk/lib/_internal/pub/lib/src/utils.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.
 
 /// Generic utility functions. Stuff that should possibly be in core.
 library pub.utils;
 
 import 'dart:async';
 import 'dart:io';
 import 'dart:isolate';
@@ skipping 54 matching lines @@
       completed = true;
       _completer.completeError(e);
     }));
 
     return task;
   }
 
   Future<List> get future => _completer.future;
 }
 
+/// Like [new Future], but avoids around issue 11911 by using [new Future.value]
+/// under the covers.
+Future newFuture(callback()) => new Future.value().then((_) => callback());
+
 // TODO(rnystrom): Move into String?
 /// Pads [source] to [length] by adding spaces at the end.
 String padRight(String source, int length) {
   final result = new StringBuffer();
   result.write(source);
 
   while (result.length < length) {
     result.write(' ');
   }
 
@@ skipping 315 matching lines @@
 /// * Even if the former is guarded against by adding asynchronous operations,
 ///   returning a value through the [Future] chain can still cause a stack
 ///   overflow.
 Future resetStack(fn()) {
   // Using a [Completer] breaks the [Future] chain for the return value and
   // avoids the third case described above.
   var completer = new Completer();
 
   // Using [new Future] adds an asynchronous operation that works around the
   // first and second cases described above.
-  new Future(fn).then((val) {
+  newFuture(fn).then((val) {
     runAsync(() => completer.complete(val));
   }).catchError((err) {
     runAsync(() => completer.completeError(err));
   });
   return completer.future;
 }
 
 /// The subset of strings that don't need quoting in YAML. This pattern does
 /// not strictly follow the plain scalar grammar of YAML, which means some
 /// strings may be unnecessarily quoted, but it's much simpler.
@@ skipping 80 matching lines @@
     error is DirectoryException ||
     error is FileException ||
     error is HttpException ||
     error is HttpException ||
     error is LinkException ||
     error is OSError ||
     error is ProcessException ||
     error is SocketException ||
     error is WebSocketException;
 }