Also wrap stdin/stdout/stderr on Process.

runtime/bin/stdio_patch.dart

Index: runtime/bin/stdio_patch.dart
diff --git a/runtime/bin/stdio_patch.dart b/runtime/bin/stdio_patch.dart
index c90e557c1648402405ef128ac714534079afe959..cb1c920ccc6e8bea1081864f91a05b021cc46ab8 100644
--- a/runtime/bin/stdio_patch.dart
+++ b/runtime/bin/stdio_patch.dart
@@ -8,9 +8,9 @@ patch class _StdIOUtils {
       case _STDIO_HANDLE_TYPE_TERMINAL:
       case _STDIO_HANDLE_TYPE_PIPE:
       case _STDIO_HANDLE_TYPE_SOCKET:
-        return new _Stdin(new _Socket._readPipe(0));
+        return new _StdStream(new _Socket._readPipe(0));
       case _STDIO_HANDLE_TYPE_FILE:
-        return new _Stdin(new _FileStream.forStdin());
+        return new _StdStream(new _FileStream.forStdin());
       default:
         throw new FileIOException("Unsupported stdin type");
     }