Regenerate pub sources.

sdk/lib/_internal/pub_generated/lib/src/command/downgrade.dart

Index: sdk/lib/_internal/pub_generated/lib/src/command/downgrade.dart
diff --git a/sdk/lib/_internal/pub_generated/lib/src/command/downgrade.dart b/sdk/lib/_internal/pub_generated/lib/src/command/downgrade.dart
index 5e340a84a41eb261144ba10ea7dda08f43ea7597..1de7e16e5ea3791379ee1b154cf7f8e005c97163 100644
--- a/sdk/lib/_internal/pub_generated/lib/src/command/downgrade.dart
+++ b/sdk/lib/_internal/pub_generated/lib/src/command/downgrade.dart
@@ -1,25 +1,37 @@
+// 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.
+
 library pub.command.downgrade;
+
 import 'dart:async';
+
 import '../command.dart';
 import '../log.dart' as log;
 import '../solver/version_solver.dart';
+
+/// Handles the `downgrade` pub command.
 class DowngradeCommand extends PubCommand {
   String get description =>
       "Downgrade the current package's dependencies to oldest versions.\n\n"
           "This doesn't modify the lockfile, so it can be reset with \"pub get\".";
   String get usage => "pub downgrade [dependencies...]";
   bool get takesArguments => true;
+
   bool get isOffline => commandOptions['offline'];
+
   DowngradeCommand() {
     commandParser.addFlag(
         'offline',
         help: 'Use cached packages instead of accessing the network.');
+
     commandParser.addFlag(
         'dry-run',
         abbr: 'n',
         negatable: false,
         help: "Report what dependencies would change but don't change any.");
   }
+
   Future onRun() {
     final completer0 = new Completer();
     scheduleMicrotask(() {
@@ -32,7 +44,7 @@ class DowngradeCommand extends PubCommand {
           try {
             x0;
             join0() {
-              completer0.complete(null);
+              completer0.complete();
             }
             if (isOffline) {
               log.warning(
@@ -42,14 +54,12 @@ class DowngradeCommand extends PubCommand {
             } else {
               join0();
             }
-          } catch (e0) {
-            completer0.completeError(e0);
+          } catch (e0, s0) {
+            completer0.completeError(e0, s0);
           }
-        }, onError: (e1) {
-          completer0.completeError(e1);
-        });
-      } catch (e2) {
-        completer0.completeError(e2);
+        }, onError: completer0.completeError);
+      } catch (e, s) {
+        completer0.completeError(e, s);
       }
     });
     return completer0.future;