Revert "Revert "Make stdout/stderr async""

sdk/lib/_internal/compiler/js_lib/io_patch.dart

Index: sdk/lib/_internal/compiler/js_lib/io_patch.dart
diff --git a/sdk/lib/_internal/compiler/js_lib/io_patch.dart b/sdk/lib/_internal/compiler/js_lib/io_patch.dart
index b6400f3c69350ea57f4f9f39f6fdc8cd208df3e5..c2c218a05442e76fd61515c59255c546be4d8619 100644
--- a/sdk/lib/_internal/compiler/js_lib/io_patch.dart
+++ b/sdk/lib/_internal/compiler/js_lib/io_patch.dart
@@ -495,15 +495,15 @@ class Stdin {
 @patch
 class Stdout {
   @patch
-  bool _hasTerminal(int fd) {
+  bool get hasTerminal {
     throw new UnsupportedError("Stdout.hasTerminal");
   }
   @patch
-  int _terminalColumns(int fd) {
+  int get terminalColumns {
     throw new UnsupportedError("Stdout.terminalColumns");
   }
   @patch
-  int _terminalLines(int fd) {
+  int get terminalLines {
     throw new UnsupportedError("Stdout.terminalLines");
   }
 }