Revert "Use native async/await support in pub."

sdk/lib/_internal/pub_generated/lib/src/barback/foreign_transformer.dart

Index: sdk/lib/_internal/pub_generated/lib/src/barback/foreign_transformer.dart
diff --git a/sdk/lib/_internal/pub/lib/src/barback/foreign_transformer.dart b/sdk/lib/_internal/pub_generated/lib/src/barback/foreign_transformer.dart
similarity index 89%
copy from sdk/lib/_internal/pub/lib/src/barback/foreign_transformer.dart
copy to sdk/lib/_internal/pub_generated/lib/src/barback/foreign_transformer.dart
index 7816a98e19ee01ee45d4c70f9bc49c0a2c674a67..6ab11145b9cfda2edfdd1f5f1c35adc107eca781 100644
--- a/sdk/lib/_internal/pub/lib/src/barback/foreign_transformer.dart
+++ b/sdk/lib/_internal/pub_generated/lib/src/barback/foreign_transformer.dart
@@ -46,8 +46,8 @@ class _ForeignTransformer extends Transformer {
   String toString() => _toString;
 }
 
-class _ForeignDeclaringTransformer extends _ForeignTransformer
-    implements DeclaringTransformer {
+class _ForeignDeclaringTransformer extends _ForeignTransformer implements
+    DeclaringTransformer {
   _ForeignDeclaringTransformer(Map map)
       : super(map);
 
@@ -59,8 +59,8 @@ class _ForeignDeclaringTransformer extends _ForeignTransformer
   }
 }
 
-class _ForeignLazyTransformer extends _ForeignDeclaringTransformer
-    implements LazyTransformer {
+class _ForeignLazyTransformer extends _ForeignDeclaringTransformer implements
+    LazyTransformer {
   _ForeignLazyTransformer(Map map)
       : super(map);
 }
@@ -110,9 +110,8 @@ class _ForeignDeclaringAggregateTransformer extends _ForeignAggregateTransformer
   }
 }
 
-class _ForeignLazyAggregateTransformer
-    extends _ForeignDeclaringAggregateTransformer
-    implements LazyAggregateTransformer {
+class _ForeignLazyAggregateTransformer extends
+    _ForeignDeclaringAggregateTransformer implements LazyAggregateTransformer {
   _ForeignLazyAggregateTransformer(Map map)
       : super(map);
 }
@@ -126,9 +125,9 @@ class _ForeignGroup implements TransformerGroup {
 
   _ForeignGroup(TransformerConfig config, Map map)
       : phases = map['phases'].map((phase) {
-          return phase.map((transformer) => deserializeTransformerLike(
-              transformer, config)).toList();
-        }).toList(),
+        return phase.map(
+            (transformer) => deserializeTransformerLike(transformer, config)).toList();
+      }).toList(),
         _toString = map['toString'];
 
   String toString() => _toString;
@@ -138,8 +137,9 @@ class _ForeignGroup implements TransformerGroup {
 /// or a [TransformerGroup].
 deserializeTransformerLike(Map map, TransformerConfig config) {
   var transformer;
-  switch(map['type']) {
-    case 'TransformerGroup': return new _ForeignGroup(config, map);
+  switch (map['type']) {
+    case 'TransformerGroup':
+      return new _ForeignGroup(config, map);
     case 'Transformer':
       transformer = new _ForeignTransformer(map);
       break;
@@ -158,7 +158,8 @@ deserializeTransformerLike(Map map, TransformerConfig config) {
     case 'LazyAggregateTransformer':
       transformer = new _ForeignLazyAggregateTransformer(map);
       break;
-    default: assert(false);
+    default:
+      assert(false);
   }
 
   if (transformer is Transformer) {