Revert "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/lib/src/validator/size.dart b/sdk/lib/_internal/pub_generated/lib/src/validator/size.dart
similarity index 85%
copy from sdk/lib/_internal/pub/lib/src/validator/size.dart
copy to sdk/lib/_internal/pub_generated/lib/src/validator/size.dart
index 0b8d05f2f55c35001d62418c883ffa656ceab2c8..129fea9f08827265d45e3439ea5eac3694051ed2 100644
--- a/sdk/lib/_internal/pub/lib/src/validator/size.dart
+++ b/sdk/lib/_internal/pub_generated/lib/src/validator/size.dart
@@ -18,14 +18,14 @@ class SizeValidator extends Validator {
   final Future<int> packageSize;
 
   SizeValidator(Entrypoint entrypoint, this.packageSize)
-    : super(entrypoint);
+      : 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.");
+      errors.add(
+          "Your package is $sizeInMb MB. Hosted packages must be " "smaller than 10 MB.");
     });
   }
 }