Use native async/await support in pub.

sdk/lib/_internal/pub_generated/lib/src/validator/size.dart

Index: sdk/lib/_internal/pub_generated/lib/src/validator/size.dart
diff --git a/sdk/lib/_internal/pub_generated/lib/src/validator/size.dart b/sdk/lib/_internal/pub_generated/lib/src/validator/size.dart
deleted file mode 100644
index 129fea9f08827265d45e3439ea5eac3694051ed2..0000000000000000000000000000000000000000
--- a/sdk/lib/_internal/pub_generated/lib/src/validator/size.dart
+++ /dev/null
@@ -1,32 +0,0 @@
-// 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 pub.validator.size;
-
-import 'dart:async';
-import 'dart:math' as math;
-
-import '../entrypoint.dart';
-import '../validator.dart';
-
-/// The maximum size of the package to upload (10 MB).
-const _MAX_SIZE = 10 * 1024 * 1024;
-
-/// A validator that validates that a package isn't too big.
-class SizeValidator extends Validator {
-  final Future<int> packageSize;
-
-  SizeValidator(Entrypoint entrypoint, this.packageSize)
-      : super(entrypoint);
-
-  Future validate() {
-    return packageSize.then((size) {
-      if (size <= _MAX_SIZE) return;
-      var sizeInMb = (size / math.pow(2, 20)).toStringAsPrecision(4);
-      errors.add(
-          "Your package is $sizeInMb MB. Hosted packages must be " "smaller than 10 MB.");
-    });
-  }
-}
-