Remove dart:json

tests/standalone/io/stdin_sync_script.dart

Index: tests/standalone/io/stdin_sync_script.dart
diff --git a/tests/standalone/io/stdin_sync_script.dart b/tests/standalone/io/stdin_sync_script.dart
index 42b648e42b09e6677754080baa0601617a834e82..c29de2f7ae68294c0f1c014fa35b1a48d577b36f 100644
--- a/tests/standalone/io/stdin_sync_script.dart
+++ b/tests/standalone/io/stdin_sync_script.dart
@@ -4,13 +4,14 @@
 
 import "dart:convert";
 import "dart:io";
-import "dart:json";
 
 void main(List<String> arguments) {
   int i = 0;
   String line;
   while ((line = stdin.readLineSync(encoding: UTF8)) != null) {
-    if (parse(arguments[i]) != line) throw "bad line at $i: ${line.codeUnits}";
+    if (JSON.decode(arguments[i]) != line) {
+      throw "bad line at $i: ${line.codeUnits}";
+    }
     i++;
   }
   if (i != arguments.length) throw "expect ${arguments.length} lines";