Allow Directory.create to create all missing path components.

utils/tests/pub/test_pub.dart

Index: utils/tests/pub/test_pub.dart
diff --git a/utils/tests/pub/test_pub.dart b/utils/tests/pub/test_pub.dart
index 3c62afcc079494b1bf7c98f0096c36b364a25556..3b45775d9316c60040f8e4daa7fd1a0b2e0e728b 100644
--- a/utils/tests/pub/test_pub.dart
+++ b/utils/tests/pub/test_pub.dart
@@ -1157,7 +1157,9 @@ class TarFileDescriptor extends Descriptor {
       return create(tempDir);
     }).then((tar) {
       var sourceStream = tar.openInputStream();
-      pipeInputToInput(sourceStream, sinkStream, tempDir.deleteRecursively);
+      pipeInputToInput(sourceStream,
+                       sinkStream,
+                       () => tempDir.delete(recursive: true));
     });
     return sinkStream;
   }