Use patching for dart:io.

runtime/bin/stdio_patch.dart

Index: runtime/bin/stdio_patch.dart
diff --git a/lib/html/dartium/nativewrappers.dart b/runtime/bin/stdio_patch.dart
similarity index 50%
copy from lib/html/dartium/nativewrappers.dart
copy to runtime/bin/stdio_patch.dart
index 44ab39e1ac7567e620f8402b566e4b492836d41e..bcdc671aea511af35ac17df1a4bbad222ffde869 100644
--- a/lib/html/dartium/nativewrappers.dart
+++ b/runtime/bin/stdio_patch.dart
@@ -2,7 +2,9 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-#library('nativewrappers');
-
-class NativeFieldWrapperClass1 {
+patch class _StdIOUtils {
+  /* patch */ static _getStdioHandle(Socket socket, int num)
+      native "Socket_GetStdioHandle";
+  /* patch */ static _getStdioHandleType(int num)
+      native "File_GetStdioHandleType";
 }