Remove the LineTransformer from dart:io

tests/standalone/io/process_stdin_transform_unsubscribe_script.dart

Index: tests/standalone/io/process_stdin_transform_unsubscribe_script.dart
diff --git a/tests/standalone/io/process_stdin_transform_unsubscribe_script.dart b/tests/standalone/io/process_stdin_transform_unsubscribe_script.dart
index 071112488a9d03915796316a3d51a058b0a830cf..06b42d8c610d4292950ab92c7a0357881a91af12 100644
--- a/tests/standalone/io/process_stdin_transform_unsubscribe_script.dart
+++ b/tests/standalone/io/process_stdin_transform_unsubscribe_script.dart
@@ -4,13 +4,14 @@
 //
 // Utility script to echo stdin to stdout or stderr or both.
 
+import "dart:convert";
 import "dart:io";
 
 main() {
   var subscription;
   subscription = stdin
       .transform(new StringDecoder())
-      .transform(new LineTransformer())
+      .transform(new LineSplitter())
       .listen((String line) {
           // Unsubscribe after the first line.
           subscription.cancel();