Stop working around issue 7790 in pub.

utils/pub/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 utils;
 
 import 'dart:async';
 import 'dart:crypto';
 import 'dart:isolate';
@@ skipping 100 matching lines @@
   return completer.future;
 }
 
 /// Configures [future] so that its result (success or exception) is passed on
 /// to [completer].
 void chainToCompleter(Future future, Completer completer) {
   future.then((value) => completer.complete(value),
       onError: (e) => completer.completeError(e.error, e.stackTrace));
 }
 
-// TODO(nweiz): remove this when issue 7790 is fixed.
-/// Like [Future.whenComplete], except that [action] may return a [Future]. If
-/// it does, the returned [Future] won't complete until [action]'s [Future]
-/// completes.
-///
-/// The returned [Future] always has the same value as [future].
-Future asyncWhenComplete(Future future, Future action()) {
-  Future futurify(Future future) {
-    if (future != null) return future;
-    return new Future.immediate(null);
-  }
-
-  return future.then((result) => futurify(action()).then((_) => result),
-      onError: (e) {
-    return futurify(action()).then((_) {
-      throw e;
-    });
-  });
-}
-
 // TODO(nweiz): unify the following functions with the utility functions in
 // pkg/http.
 
 /// Like [String.split], but only splits on the first occurrence of the pattern.
 /// This will always return an array of two elements or fewer.
 List<String> split1(String toSplit, String pattern) {
   if (toSplit.isEmpty) return <String>[];
 
   var index = toSplit.indexOf(pattern);
   if (index == -1) return [toSplit];
@@ skipping 63 matching lines @@
 /// AsyncErrors. This unwraps them to find the real originating stack trace.
 getRealStackTrace(error) {
   var trace = null;
   while (error is AsyncError) {
     trace = error.stackTrace;
     error = error.error;
   }
 
   return trace;
 }