Use the dart:async Stream API thoroughly in Pub.

pkg/http/lib/src/byte_stream.dart

Index: pkg/http/lib/src/byte_stream.dart
diff --git a/pkg/http/lib/src/byte_stream.dart b/pkg/http/lib/src/byte_stream.dart
index 3de17efad2b7644b22f482eff9cf3cb143288ef2..72a53a0e066fc5cc3726ad216d074fbe613add84 100644
--- a/pkg/http/lib/src/byte_stream.dart
+++ b/pkg/http/lib/src/byte_stream.dart
@@ -33,4 +33,7 @@ class ByteStream extends StreamView<List<int>> {
   /// [encoding], which defaults to `Encoding.UTF_8`.
   Future<String> bytesToString([Encoding encoding=Encoding.UTF_8]) =>
       toBytes().then((bytes) => decodeString(bytes, encoding));
+
+  Stream<String> toStringStream([Encoding encoding=Encoding.UTF_8]) =>
+      mappedBy((bytes) => decodeString(bytes, encoding));
 }