Fix multiline problem in printer_callback_test.

pkg/js_ast/test/printer_callback_test.dart

Index: pkg/js_ast/test/printer_callback_test.dart
diff --git a/pkg/js_ast/test/printer_callback_test.dart b/pkg/js_ast/test/printer_callback_test.dart
index 4d174458b9911ebfedd5bf135e4a34db242bdc8b..a7cf391aed37895c36120809dc701bdabe795f3d 100644
--- a/pkg/js_ast/test/printer_callback_test.dart
+++ b/pkg/js_ast/test/printer_callback_test.dart
@@ -195,7 +195,9 @@ void check(TestCase testCase) {
     if (mode == TestMode.INPUT) return;
     Context context = new Context(mode);
     new Printer(options, context).visit(node);
-    expect(context.getText(), equals(expectedOutput),
+    // TODO(johnniwinther): Remove `replaceAll(...)` when dart2js behaves as the
+    // VM on newline in multiline strings.
+    expect(context.getText(), equals(expectedOutput.replaceAll('\r\n', '\n')),
         reason: "Unexpected output for $code in $mode");
   });
 }