Get rid of 'close' on process. It is very easy to use incorrectly and cut off data from your stream…

tests/standalone/io/process_check_arguments_test.dart

Index: tests/standalone/io/process_check_arguments_test.dart
diff --git a/tests/standalone/io/process_check_arguments_test.dart b/tests/standalone/io/process_check_arguments_test.dart
index cc0f5e73f6b20cae5afe1a343cb1849b89cccfda..1e97c8d7a20593ed2262031e9dbdde53875458b5 100644
--- a/tests/standalone/io/process_check_arguments_test.dart
+++ b/tests/standalone/io/process_check_arguments_test.dart
@@ -10,8 +10,10 @@ test(args) {
   future.then((process) {
     process.onExit = (exitCode) {
       Expect.equals(0, exitCode);
-      process.close();
     };
+    // Drain stdout and stderr.
+    process.stdout.onData = process.stdout.read;
+    process.stderr.onData = process.stderr.read;
   });
 }